CHURCHILL LIVINGSTONE An imprint of Elsevier Limited © Pearson Professional Limited 1995 © 2002, Elsevier Limited. All rights reserved. The rights of Linda M. Merriman and Warren Turner to be identified as editors of this work has been asserted by them in accordance with the Copyright, Designs and Patents Act 1988 No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without either the prior permission of the publishers or a licence permitting restricted copying in the United Kingdom issued by the Copyright Licensing Agency, 90 Tottenham Court Road, London WIT 4LP. Permissions may be sought directly from Elsevier's Health Sciences Rights Department in Philadelphia, USA: phone: (+1) 215 238 7869, fax: (+1) 215 238 2239, email:
[email protected]. You may also complete your request on-line via the Elsevier homepage (http://www.elsevier.com).by selecting 'Customer Support' and then 'Obtaining Permissions'. First edition 1995 Second edition 2002 Reprinted 2005 ISBN 0 443 07112 8 British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloguing in Publication Data A catalogue record for this book is available from the Library of Congress Note Medical knowledge is constantly changing. As new information becomes available, changes in treatment, procedures, equipment and the use of drugs become necessary. The authors and the publishers have taken care to ensure that the information given in this text is accurate and up to date. However, readers are strongly advised to confirm that the information, especially with regard to drug usage, complies with the latest legislation and standards of practice.
-
health sciences
www.elsevierhealth.com
Working together to grow libraries in developing countries
www.elsevier.com
I
ELSEVIER
f,«"~~~~~
Printed in China
www.bookaid.org
I www.sabre.org
Sabre Foundation
The publishers policy istouse papermanufactured from sustainable forests
I
Contributors
Robert L Ashford
C Payne DipPod (NZ) MPH
BA BEd MA MMedSci PhD DPodM MChS
Lecturer, Department of Podiatry, School of Human Biosciences, La Trobe University, Melbourne, Australia
Professor of Podiatry, Health and Social Care Research Centre, Faculty of Health and Community Care, University of Central England, UK Paul Beeson BSc(Hons) MSc DPodM Senior Lecturer, Northampton School of Podiatry, University College Northampton, UK Ivan Bristow MSc(Oxon) BSc(Hons) DPodM MChS Senior Lecturer, Faculty of Applied Sciences, University College Northampton, UK
A Percivall Senior Lecturer, School of Podiatry, University College Northampton, UK I Reilly DPodM BSc SRCh FCPod(S) Cert MHS DMS Senior Lecturer I Podiatric Surgeon, School of Podiatry, University College Northampton, UK
C J Griffith BSc(Hons) DPodM SRCh Private Practitioner, The Manse Health Centre, UK
Ian F Turbutt BSc(Hons) FChS FPodA FCPods Specialist in Podiatric Surgery, The Manor Hospital, Bedford; Ext. Lecturer in Podiatric Radiology, University of Brighton and University of Southampton, UK
Mary Hanley BSc(Hons) Psychology MSc PhD Senior Lecturer (Health Psychology & Research Methods), University College Northampton, UK
R Turner MB ChB MRCP Consultant Dermatologist, Churchill Hospital, Oxford, UK
Linda Merriman PhD MPhil DPodM MChS CertEd Dean, School of Health and Social Sciences, Coventry University, UK
Warren Turner BSc(Hons) DPodM Associate Dean, School of Podiatry, University College Northampton, UK
JMcLeod Roberts BSc(Hons) MSc DPodM Senior Lecturer, Northampton School of Podiatry, University College Northampton, UK Patricia Nesbitt DPodM MChS PGD(BioEng) Senior Lecturer, Faculty of Applied Sciences, University College Northampton, UK
Ben Yates MSc (Sports Injuries) BSc(Hons) FCPod Head, Podiatry Department, La Trobe University, Melbourne, Australia
Preface
Many textbooks make reference to the assessment of the lower limb but very few are dedicated entirely to this purpose. Those that are tend to focus on only one of the components of the process, e.g. skin disorders or on a specific client group such as paediatrics. The purpose of this book is to produce a textbook which encompasses all aspects of lower limb assessment. Problems affecting the lower limb can lead to discomfort, pain, reduction or loss of mobility and loss of time from work. Effective and efficient management of these problems can only be based on a thorough assessment. Throughout the book the term 'practitioner' is used in its broadest sense to denote any person who has an interest in the management of lower limb problems. Although the podiatrist has a natural claim to specialising in caring for the foot, the range of practitioners with an interest in the lower limb includes bioengineers, diabetologists, general medical practitioners, nurses, occupational therapists, orthopaedic surgeons, orthotists, physiotherapists and rheumatologists. This is the second edition of this textbook and, like the first edition, it is divided into four parts: Approaching the Patient, Systems Examination, Laboratory and Hospital Investigations and Specific Client Groups. Approaching the Patient provides an introduction to the assessment process and covers in detail the assessment interview, the presenting problem and the reliability and validity of clinical measurement. For the second edition these chapters have been reviewed and updated.
Systems Examination covers the separate components of lower limb assessment: medical and social history, vascular, neurological, orthopaedics, skin and appendages and footwear assessments. Details relating to anatomy and physiology have been discussed where relevant. Again, the chapters in this section have been updated as part of the second edition. The chapter on the assessment of skin and its appendages has been rewritten, as has the chapter on the locomotor system, which has been renamed orthopaedic assessment to reflect more accurately the content of the chapter. Laboratory and Hospital Investigations focuses on those tests which may be performed to confirm, support or clarify the clinical examination: blood analysis, urine analysis, microbial identification, histopathology, radiographic imaging and methods of quantifying gait and foot-ground interface systems. These chapters have been updated for the second edition. Reliance on tests without the appropriate clinical examination is unwise, creates higher costs, may worry the patient unnecessarily and overworks support departments. It is intended that this part of the book demonstrates when and how these tests can be used to aid the assessment process. The last part of the book, Specific Client Groups, looks at the main areas of foot disease: the at-risk foot, the child's foot, sport injuries and the painful foot. For the second edition two new chapters have been added to this section: assessment of the elderly and pre- and postoperative assessment. The addition of these chapters reflects the developments within podiatry. The elderly
x
PREFACE
form by far the largest client group receiving foot treatment; it is, therefore, important that the specific needs of this client group are addressed in this textbook. Over the last 10 years there has been a growth in the number of surgical procedures performed, under local analgesia, by podiatrists. Assessing a patient for surgery under local analgesia requires the practitioner to be aware of the specific issues related to this type of treatment as they do differ from those resulting from surgery under general anaesthesia. Although Systems Examination covers the range of assessments and can be applied to all age groups, the assessment of children and sports people is worthy of independent discussion. Pain in the foot can arise due to a multitude of factors, affects all age groups and has a highly morbid affect on our lives; for this reason, it has been given a separate chapter. The early diagnosis of the at-risk foot is recognised as a means of reducing morbidity, mortality and minimising the cost of in-hospital care for these patients.
Case histories and comments support some of the chapters, particularly those in Systems Examination and Specific Client Groups. These have been used to illustrate certain points and reflect real life experiences. Where appropriate, black and white photographs, figures and tables have also been used to support and further illustrate points raised in the text. A section of colour plates has been specifically used to support Chapters 6, 9 and 17. Each chapter has been referenced and some indicate Further Reading. Clearly there is more than one approach to undertaking an assessment. Assessment of the Lower Limb has been written to support good practice in a wide range of outlets for all professionals with an interest in the foot. Whatever approach the practitioner adopts, it is hoped that this text will be a valuable asset.
Linda Merriman, Warren Turner, 2002
Acknowledgements
We are indebted to those who have given their help and encouragement throughout the development and production of this second edition: in particular, our family and friends. A big thank you to all the contributors for their time and effort in updating and/or rewriting their chapters. We would also like to thank Ann Marie Carr for her help with the new chapter on assessment of the elderly.
This book is dedicated to Jackie McLeod Roberts in recognition of her contribution to podiatry and in particular her work in the Ukraine, developing and improving footcare services for people with diabetes. Jackie's pioneering work has made a significant difference to these people.
Plate 1 An ischaemic foot. The superficial tissues are atrophied. The fifth ray has been excised.
Plate 2 Typical ischaemic ulceration overlying a hallux abductovalgus in a patient with chronic peripheral vascular disease.
Plate 4 Telangiectasias: distortion of the superficial venules secondary to varicosity.
Plate 3 'Dry' gangrene, involving two toes. The necrotic area is surrounded by a narrow band of inflammation. The toes have become mummified, due to loss of the local blood supply.
Plate 5 Atrophie blanche (white patches), which occurs in association with chronic venous hypertension and venous ulcers.
Plate 7 Healed venous ulcer that had been present for 2 years.
Plate 6 Gravitational (varicose, stasis) eczema and haemosiderosis.
Plate 8 Venous ulceration in association with gross oedema and haemosiderosis (from Wilkinson J, Shaw S, Fenton 0 1993 Colour guide to dermatology. Churchill Livingstone, Edinburgh, Figure 179).
Plate 9 Histology section of normal hairy skin stained with haematoxylin and eosin. Light microscopy x 60.
Plate 11 Plate 10
Subungual exostosis affecting the second toe.
Koebner phenomenon in psoriasis due to injury.
Plate 13 Dorsal corn.
Plate 12 Extravasation within callus due to prolonged high pressure .
.. Plate 14
Plantar keratoderma.
Plate 15
Bullous pemphigoid.
Plate 17
Lichen planus.
Plate 18
Necrobiosis Iipoidica.
Plate 16
Plantar pustular psoriasis.
Plate 19
Acute contact dermatitis to adhesives in footwear.
CHAPTER TITLE
Plate 20 patient.
Plate 21 area.
Pseudomonas infection affecting the interdigital
Plate 23
Tinea pedis affecting the dorsum of the foot.
Extensive plantar warts in an immunosuppressed
Plate 22
Pitted keratolysis of the heel.
Plate 24
Interdigital melanoma.
5
6
PART TITLE
Plate 25
Pyogenic granuloma under the nail.
Plate 27 The sample of urine on the left is normal; the sample on the right is cloudy and tinged with blood, indicating infection.
PRINT DATE:
Plate 26 Metastatic lesion (secondary from a lung tumour).
02/92
00 NOT USE AFTER: 00 NOT EXPO$!: TO DIRECT SUNLIGHT READ PRODUCT INSERT BEFORE USE.
________ 11 TESTS AND READING TIMES (to be read in the ctireetlon of arrow)
L£UCoCYTES
TRACE
NEG.
2 minutes NITRITE
60seconds PRoTE1H
&D seconds pH
60seconds NON·
BLOOD
&Dseconds
SPECIRC GRAVITY 45seconds
KfTONE
GLUCOSE
30seconds
Ii@nk,''''''
HAEMOI.Yleo HAEMDLY2£O lllACE TRACE
• •• NEG.
40seconds
Plate 28 Multistix 8SG: the range of biochemical tests available from one urine sample (reproduced by kind permission of Bayer Diagnostics UK Ltd).
02194
•
NEG.
~
MODERATE
LAROE
••
5'
j
Unloading
.sE 120 (J)
c
80
40
o
5
10
15
Load kg
Figure 4.1 Hysteresis from elastomeric pressure transducer. Pressure is recorded against load applied for static calibration for a VP1 pressure pad. The plot shows loading and unloading as two curves. The hysteresis is represented by the gap between the curves (adapted from Tollafield 1990).
CLINICAL MEASUREMENT
The type of pressure transducer used by each system should also be considered. Resistive, piezoelectric and capacitance sensors convert mechanical signals into electrical signals for processing. The characteristics of transducers must be matched to the type of data the practitioner wishes to collect. The principles of hysteresis and repeatability have already been described. Spacial resolution, sampling frequency and dynamic response are other important characteristics described below. Practitioners requiring further information are directed to a very comprehensive review of pressure sensors by Urry (1999). Spacial resolution. This refers to the number of sensors in one square centimetre in a homologous matrix. If spacial resolution is low, smaller anatomical features such as the lesser metatarsal heads or toes may be missed because there is greater spacing between individual sensors. Some in-shoe methods do not have a matrix of sensors but a number of separate or discrete transducers giving a very low spacial resolution. Problems with accurate placement of these transducers on the skin overlying the metatarsal heads was highlighted by comparison with data from the F-Scan high-resolution matrix insole sensor (Lord et aI1992). The discrete transducers were shown to be out of position by as much as 20mm. Sampling frequency. This refers to the number of times each individual sensor is scanned during data collection. Events which occur very quickly in the stance phase of gait may be missed if sampling frequency is low. For walking a sampling frequency of 50 Hz (50 times per second) is appropriate, whereas a higher sampling rate of 200 Hz is required for running. The dynamic range. This should permit sampling of both high and low pressures expected in the patient cohort. If this were not the case then pressures occurring outside the range would be missed. Particular care is required with neuropathic patients as very high pressures are likely to saturate the sensors at their upper limit. Conversely, the soling materials in trainer footwear may be very shock absorbent and very low pressures may be missed.
47
Measurement instrumentation is prone to ageing and wear and tear, increasing the potential for error. Obvious changes in mechanical instruments may be noticed where the measurement scale becomes difficult to read, or its components become damaged or loose. Electronic components tend to age less noticeably. Noise is generated by electrical circuitry and it tends to increase as equipment ages. Everyday examples of noise include the background hum of audio speakers, or interference with visual information on a display monitor, rather like the lines produced on a television screen as an unsuppressed motor vehicle passes by. It is important to ensure that intrinsic noise produced by the instrumentation and electrical equipment in the vicinity does not interfere significantly with measurements. Careful use, monitoring and maintenance of equipment is essential if clinically useful measurements are to be obtained.
The practitioner Errors made by the practitioner can be reduced if a good practitioner-patient relationship is established. Effective communication and patient compliance is essential. Efficiency and confidence are usually transferred to the patient through verbal and non-verbal communication channels. Instructions given to patients must be clear, so that they understand exactly what they must do. Children, ethnic minorities and the physically and mentally disabled usually require more careful and considered approaches. Adequate time must be allowed for the measurements to be completed satisfactorily. Qualitative measurements
Qualitative measurements involve an internal appreciation and processing of the observations made. Qualitative techniques are subjective in nature and mainly involve the perceptions of sight, hearing and touch. Some senses are more acute in some individuals than in others. Different life experiences, age, education, state of health or mind and environmental factors will affect these perceptions. Qualitative measurements
48
APPROACHING THE PATIENT
are therefore more prone to bias errors in practitioners than are quantitative measures. An awareness of the problems associated with subjectivity is important, because different individuals may perceive the same observation in different ways. Often, preconceived ideas lead to mistakes, as illustrated in Figure 4.2A. When first seen most people read the legends incorrectly as 'Paris in the spring', 'Once in a lifetime', and 'Bird in the hand'. We have a tendency to see what we expect to see and ignore what we consider unimportant. This may happen in diagnosis, when a feature associated with a particular condition is given greater importance than it should receive and assumptions lead to a rapid, poorly considered diagnosis. It may be that other clinical features indicate a different pathology but these may go unnoticed, be ignored or be
regarded as of little significance. By remaining as objective as possible and adopting a systematic problem-solving approach this tendency will be reduced. The brain may interpret the same observation in different ways, as shown in Figure 4.2B. The same observation may not only differ between individuals but differ in the same individual on different occasions or as they make a closer study. Some quantitative measurement procedures depend on some subjective decisions by the practitioner. The location of pulses, anatomical landmarks and alignment of instrumentation all rely on subjectivity, thus increasing the potential for bias error. It is important to be aware of the subjective qualitative factors which may impair objective measurement so that attempts can be made to control them. Vision
A
B Figure 4.2 A. The three triangles. Failure to see the duplicated words is common. We see only what we want to see B. Howald is she? Some observers see a young woman, others an old woman. The chin and neck of the former become the nose and mouth of the latter and vice versa (Munro & Edwards 1990).
Vision plays a major part in measurement. During clinical training a student practitioner develops a 'trained eye'. Recognition of pathology develops with time and practice into a fine skill, where even subtle signs may alert the practitioner to a problem. Visual information may be impaired if lighting is inadequate. Apart from the more obvious difficulties caused where lighting levels are low, shadows cast on to a part of the limb may adversely affect subjective aspects during biomechanical examination. Eyeballing describes a subjective visual technique that can be used to align joints before measurement, or to identify midpoints across skin surfaces as goniometric reference points. Passive examination of the subtalar joint range of motion and neutral position is considered to be an important element in understanding abnormal function of the foot. Inappropriate placement of reference lines, particularly on the curved surface of the back of the leg, is more likely to occur if one side of the leg is adequately lit and the other is not. A true vertical bisection of the leg may not be obtained. Consequently, the proportions of inversion and eversion contributing to the total range of motion,
CLINICALMEASUREMENT 49
and determination of the neutral position, would be incorrect. Parallax error. A potential source of measurement error, parallax error is particularly associated with joint position and movement. Parallax is an apparent difference in position or direction of an object caused by a change or relative change of observation point, as shown in Figure 4.3. Viewing an object or patient at right angles will eliminate parallax error. Measurement error will increase if the measurement instrument is not aligned with the plane of motion. A 90° alignment must also be ensured
,
,
,
I I I I I I I
I I I I I I I
I I I
I
I I
I
A
tpJctfJC F B
C
o ABC
Figure 4.3 The effect of parallax on observation of the midpoint of the posterior aspect of the leg and heel A. Inappropriate positioning of the patient's leg leads to parallax error B. With the patient's leg and the practitioner's eyes correctly aligned parallax error is eliminated C. Inappropriate positioning of the practitioner's eyes leads to parallax error D. The actual and apparent midpoints obtained from the relative eye and leg positions adopted in diagrams A, Band C.
when reading analogue measurement scales. Parallax error up to 3° was noted in one study (Griffith 1988). The patient must be advised on the need for appropriate clothing if normal indoor dress inhibits a particular observation. Body parts must be clearly exposed where feasible. Shorts and a T-shirt, for example, allow a relatively uninhibited view of posture and movement. Touch
Touch involves many forms of direct and indirect (using instrumentation) physical contact with patients. During clinical examinations various components of the lower limb may be pushed, pulled, pressed, squeezed and twisted. The amount of force used is determined by feedback through the practitioner's proprioceptive pathways, the patient's response, sound and visual information. It is very subjective. The force used to test joint ranges of motion will need adjustment for different patients and different joints. Fluidity of the joints, muscle tone and the weight of the limb will all influence the force required to examine a joint effectively. Instruments used in neurological and vascular assessments must be applied to the appropriate area and with an appropriate amount of force. Using neurotips, tuning forks and cotton wool requires a systematic approach and correct technique. For instance, inadvertently tickling the patient with cotton wool when testing for light touch will be interpreted through pain pathways rather than light touch receptors, invalidating the result. Measurement of lower limb temperature can be obtained quantitatively with a digital thermometer, but most practitioners rely on touch. The practitioner's hand temperature will influence his appreciation of the patient's limb temperature. This can be demonstrated with a simple experiment. If both hands are inserted into a bowl of tepid water, having previously had one in cold and the other in hot, a clear difference in appreciation of temperature of the tepid water by each hand is noted. The subjective appreciation of temperature is therefore a relative phenomenon and a
50
APPROACHING THE PATIENT
patient's limb will feel warmer to a practitioner with cold hands than one who has warm hands.
Vowden (1999), Grasty (1999) and Baker & Rayman (1999).
Hearing
The patient
Doppler ultrasound units generate audible signals representing the velocity of blood flow. A normal arterial audio spectrum is triphasic, representing forward, reverse and forward blood flow. Considerable experience is necessary to develop the appropriate listening skills so that normal and abnormal sounds can be distinguished. However, artifacts can be produced if the application of the probe over the blood vessel is imprecise so that an artery and a vein are isonated simultaneously or the probe is not held steady. If the probe angle is incorrect the signal strength is reduced. A probe with an appropriate frequency must be selected, depending on the depth of the vessel of interest, so that adequate signal strength can be obtained. Connection to a computer with appropriate software enables the blood flow to be seen as a waveform providing a visual trace for interpretation (Fig. 4.4). Arterial and venous flows, pathological states and artifacts can be confirmed, with a permanent record produced for filing in case notes and inclusion in correspondence. Excellent accounts of the clinical use of Doppler ultrasound in the detection of peripheral vascular disease have been written by
The patient may be responsible for measurement errors for many reasons. General intelligence, mental disorder, anxiety, impaired hearing or sight or language difficulties could affect his ability to understand what is required. Patients may not follow instructions or respond appropriately or truthfully. They may be non-compliant. If the patient is anxious or annoyed, increased adrenaline (epinephrine) levels will elevate the basal metabolic rate, e.g. the pulse rate could be increased. Patients who are emotionally distressed may be less able to comply with the requirements of some types of measurement procedure. It is not unusual for patients to find difficulty in relaxing during passive biomechanical measurements. Joint ranges and fluidity of motion can appear reduced. Forefoot varus or supinatus could be erroneously diagnosed if the patient fails to relax the tibialis anterior muscle, because contraction of this muscle inverts the forefoot relative to the hindfoot. Neurological sensory tests may require a verbal response from the patient so that the result can be obtained. Assuming that the test is applied correctly, the patient must interpret the
Doppler waveforms
Velocity
===t>
Forward bloodflow
\:i\k--
Circumflex branch
B Figure 6.6 A. Small side vessels normally carry an insignificant fraction of blood into the peripheral tissues. Damage or occlusion of the major arteries alters pressure relationships to divert blood through the side vessels (collateral circulation). B. Anterior view of heart showing lack of anastomoses between arterial vessels supplying the myocardium. Left coronary artery supplies hatched area, right coronary artery supplies unhatched area. The lack of anastomoses between left and right coronary arteries explains why an occlusion of the left coronary artery can be so catastrophic.
VASCULAR ASSESSMENT
-f-----
85
Lymphatic venule with valves
Blind-ended lymphatic capillary
Figure 6.7
Diagram showing a blind-ended lymphatic capillary.
Tissue fluid
While capillaries bring blood close to all body cells, a diffusion medium is needed to enable nutrients, waste products and gases to be exchanged between the cells and the blood and lymph. This medium is tissue fluid, which is continuously forming from blood at capillary and postcapillary venular sites as a result of hydrostatic and oncotic pressures (Fig. 6.8). Some tissue fluid is reabsorbed back into these vessels, the remainder draining into the lymphatic capillaries to be returned to the general circulation.
NORMAL PHYSIOLOGY OF THE CARDIOVASCULAR SYSTEM The essential function of the CVS is to ensure that there is sufficient perfusion pressure to maintain, under all circumstances, an adequate flow of blood to the vital organs, especially the brain. This is achieved by alteration of the rate and force of contraction of the myocardium and by varying the diameter throughout the peripheral circulation. In periods of increased demand, nonvital areas will have a reduced flow and this may very well affect the lower limb.
The heart contracts about once every 0.8 seconds in a healthy resting adult. The heart beat is divided into two phases: the relaxation phase or diastole and the contraction phase or systole. Systole is the shorter of the two phases, lasting about 0.3 seconds, though with increased heart rate, the period of diastole shortens. The volume of blood ejected from each ventricle is the same and is called the stroke volume. In a healthy resting adult about 70 ml is ejected at each contraction of the ventricle. Since the normal resting heart rate is an average of 72 beats per minute, the volume ejected from each ventricle in 1 minute is approximately 5 litres and is known as the cardiac output. The myocardium has the ability to contract without nerve impulses. This property is called myogenicity and is due to the presence of specialised 'pacemaker' cells which generate spontaneous action potentials. The most important of these is the sinoatrial (SA) node, situated in the right atrium (Fig. 6.9). The action potential spreads rapidly through the other specialised conducting tissues and then out over the rest of the myocardium through gap junctions between the cells. This ensures that the cells can respond as a unit, producing a coordinated
86
SYSTEMS EXAMINATION
wave of contraction which pushes the blood in the desired direction. Apart from these specialised pathways, the septa that divide the four chambers of the heart consist of fibrous, non-conducting tissue. While the heart can contract without nervous stimulation, it is essential that it can alter its activity according to the differing demands placed upon it as mentioned earlier. One way
that this is achieved is via the autonomic system (ANS) (Ch. 7). The two branches of the ANS send fibres to the SA node. The sympathetic nerve acts on the heart via specific receptors called beta 1receptors, the action of which is to increase cardiac output by increasing both stroke volume (positive inotropy) and heart rate (positive chronotropy). The parasympathetic nerve to the heart is called the vagus and causes slowing of
Arterial end
respiring cells
HPb high OcPb high blood (protein .salts, water, cells)
water, salts and small amount proteins
HPb low OcPb high
Venous end
Blood
Tissue fluid
< HPt
> HPt
HPb OcPb
> OcPt
Fluid in (small)
Net pressure forces fluid out
OcPt
Result Fluid in Fluid in
Net pressure forces fluid in
HPb(t) = hydrostatic pressure of blood (and pressure flow) OcPb(t) = oncolic pressure of blood (b) and tissue fluid (t) oncolic pressure = oncolic pressure due to protein Figure 6.8 The process of formation and reabsorption of tissue fluid in an ideal capillary. Movement of fluid in and out of the capillary will vary according to the precise balance of pressures along the capillary at anyone time.
VASCULAR ASSESSMENT
the heart rate (negative chronotropy), acting through cholinergic receptors. At rest the parasympathetic nerve predominates, producing the average resting heart rate of 72 beats per minute. The rate is less in trained athletes and higher in children and is also affected by posture, increasing on a change from a supine to an upright position by approximately 10 beats per minute. The latter is due to compensation for the effects of gravity on blood in the peripheral vessels and is mediated through the baroreceptor reflex (Fig. 6.10). Baroreceptors are situated in both the arterial and venous components of the systemic circulation, but the arterial baroreceptors in the aortic arch and carotid body are the more important for regulation of blood pressure. They continuously monitor the level and feed this information to the cardiovascular control centre in the part of the brain stem called the medulla oblongata. As a result of this information being integrated in the medulla, compensatory adjustments are made to the action of the heart and the diameter of the arterial tree through
the sympathetic nerves, which act on the smooth muscle of the tunica media. Despite being very sensitive to changes in blood pressure, baroreceptors show a rapid adaptation to a sustained change, so that in hypertension they are triggered by a higher than normal 'operating' range. All vessels except capillaries are subject to some sympathetic influence or 'tone'. The greater the sympathetic tone, the more vasoconstriction is achieved, with vasodilation being produced by a reduction in this tone. This in turn produces a change in resistance to flow, or peripheral resistance, a change in the pressure exerted on the blood and a change in the work the heart has to do (afterload), The greatest effect is produced in the arterioles, called the resistance vessels, which as mentioned previously have the largest proportion of smooth muscle in their walls. They allow the CVS to control distribution of blood and, together with the heart, are the effector organs for the homeostatic control of blood pressure. A similar reflex exists to regulate blood volume, which in addition involves, to a greater extent,
Atrial excitation begins
Ventricular excitation complete
A
87
begins
B
Right and left branch bundles
complete
Purkinje fibres
C
o
Figure 6.9 Vertical outline of the heart, showing the SA node (A), AV node (8), bundle of His (C), Purkinje fibres (D) and spread of waves from the SA node (A-D).
88
SYSTEMS EXAMINATION
the low-pressure baroreceptors in the right atrium and where the effector organs include the kidney as well as the CVS. The aorta and pulmonary arteries are the elastic arteries, having a large proportion of elastic tissue in their walls. This distends as the bolus of blood is received from the ventricles and acts as a secondary pump during diastole when the elastic recoil propels the blood forward. The rebound causes a shock wave to travel rapidly through the blood in the arterial tree and it can be felt as a pulse wave at certain points called pressure points. The overall purpose then of all the vessels within the systemic circulation, with the exception of the capillaries, is to deliver blood with its dissolved nutrients, oxygen and hormones to the tissues and to remove metabolic waste such as carbon dioxide and urea. This transportation must meet the demands of the different tissues, which will vary in need according to their nature and level of activity. Heat is also distributed from areas such as active muscles and the liver to the rest of the body. The skin is an important organ for controlling heat loss, involving the
t
ARTERIAL PRESSURE
Arterial baroreceptors tFIRING
Reflex via medullary cardiovascular centre
... SYMPATHETIC OUTFLOW TO HEART, ARTERIOLES, VEINS
Figure 6.10 Flow chart showing the arterial baroreceptor reflex. If arterial pressure decreases the arrows in the boxes would be reversed.
superficial papillary loops and the specialised glomus bodies which can re-route blood towards or away from the skin surface. The purpose of such redirection is either to control heat loss or to ensure that superficial tissues do not suffer from ischaemia caused by coldinduced vasoconstriction. The function of the capillaries is the exchange of the substances transported to the tissues by the blood. It is here that tissue fluid plays its essential role of intermediary between blood and tissues mentioned earlier, being the ideal candidate since it bathes every cell. There is a large pressure drop across the capillary beds so that blood flowing in the venules and veins is at low pressure and needs help to get back to the heart, in the form of semilunar valves, venoconstriction and the pumping action of surrounding skeletal muscle on the deep veins. In addition, the fluctuating negative pressures in the abdomen and thorax, due to respiratory movements and the action of the heart itself, all act as suction pumps, drawing blood back into the atrial chambers. The volume of blood returning to the heart is termed the venous return or preload. It is essential that ventricular output exactly matches this venous return to avoid a transfer of blood from one circulation to the other. This matching of venous return and cardiac output is an intrinsic property of the myocardium, independent of nervous control, which is often referred to as Starling's law of the heart. The consequences of unmatched venous return to cardiac output is seen in a person with congestive heart failure, the congestion being due to a build up of blood throughout the venous tree because of a weak or damaged myocardium. In addition to returning blood to the heart, veins, because of their distensibility, act as capacitance vessels, normally holding three-fifths of the total volume of blood in the body. This can boost the circulation when necessary. The purpose of the pulmonary circulation is to deliver blood containing carbon dioxide to the lungs and exchange it via the alveolar capillaries for oxygen. Having two separate circulations also allows each to operate at a different pressure.
VASCULAR ASSESSMENT
Red blood cells contain the pigment haemoglobin, which picks up oxygen in the lungs in a stepwise manner and releases it in the tissues. Presence or absence of oxygen causes a change in shape of the haemoglobin molecule and with it a change in colour, so that oxygenated blood is bright red and deoxygenated blood is bluish-red. Red blood cells or erythrocytes are formed from stem cells in the red bone marrow and mature under the influence of kidney hormones or erythropoietins. Various factors are needed, such as iron, folic acid and vitamin BI 2 , for formation of the mature erythrocyte. The red blood cell circulates for 120 days before being broken down in the liver by phagocytic von Kupffer cells. Anaemias, reduction in the oxygen-carrying capacity of blood, can result from a defect in any part of this process. For example, damage to the bone marrow by radiation can damage the stem cells or the young red blood cells, resulting in aplastic anaemia. An autoimmune disease can destroy the parietal cells in the stomach, leading to lack of Castle's intrinsic factor, and this causes an inability to absorb vitamin BI 2 , which is required for erythropoiesis and normal nerve function. After some delay, pernicious anaemia develops.
THE VASCULAR ASSESSMENT An assessment of the vascular status of a patient consists of a general overview of the cardiovascular system and a detailed assessment of the peripheral vascular system, with particular reference to the lower limb. As mentioned previously, the peripheral vascular system consists of arteries, veins and lymphatics. The assessment of each part of the vascular tree involves: past history and current medication symptoms observable signs clinical tests hospital tests. Accurate diagnosis can often be achieved by simple observation. Research which compared • • • • •
89
diagnoses made by practitioners using observation with diagnoses arrived at with the aid of hospital tests found that the former method was almost as reliable as the latter.
GENERAL OVERVIEW OF THE CARDIOVASCULAR SYSTEM Central problems such as congestive heart failure, angina of effort and myocardial infarction as well as systemic problems such as the anaemias can all have a bearing on the diagnosis and management of lower limb problems and so must be taken into consideration (Table 6.2), although full investigation of such problems are beyond the scope of this textbook.
Past history and current medication History taking is discussed in detail in Chapter 5. Any factors which reduce or prevent tissue perfusion will not only deprive the tissue of oxygen but also of nutrients, and prevent removal of waste products, causing a condition referred to as ischaemia. The most common cause of ischaemic heart disease (IHD) is atherosclerosis of coronary vessels; therefore, IHD is often termed coronary arterial disease (CAD). The presence of CAD should alert the clinician to possible atherosclerosis in the lower limb. The
Table 6.2 perfusion
Cardiac conditions which may affect lower limb
Heart failure: left- and/or right-sided Ischaemic heart disease: angina or myocardial infarction Rheumatic fever Myocarditis Valve disorders: mitral stenosis aortic stenosis mitral regurgitation tricuspid regurgitation Infective endocarditis Congenital heart disease: septal defects valve defects coarction of the aorta Fallol's tetralogy
90
SYSTEMS EXAMINATION
Case history 6.1 A male Caucasian first presented to the clinic when 74 years old, complaining of hard skin on the balls of his feet and on the ends of his toes. He was finding it difficult to focus and so had sought treatment. His medical and social history revealed that he was a smoker and that he had had an aortic aneurysm resected when aged 73. He was taking bendroflumethiazide (bendrofluazide). A preliminary vascular assessment showed telangiectases and haemosiderosis superimposed on a normal skin colour in both lower limbs. Varicose veins were present in the right leg, hair was absent from legs and feet and the skin was dry. Nails were long but otherwise unremarkable. The feet felt cold. All four pulses were palpable and demonstrated arrhythmia. Brachial BP was 110/60 mmHg. The patient failed to attend further appointments until 3 years later, when examination revealed cyanotic feet with the right foot being worse than the left. His toenails were thickened and crumbly and oedema was present in both ankles. Pedal pulses were barely palpable.
medical history should reveal conditions which indicate coronary artery disease, such as angina of effort or previous myocardial infarctions. The presence of risk factors for atherosclerosis should also be noted, such as smoking or the presence of diabetes mellitus, hypertension or hyperlipidaemia (Case history 6.1). Anti-hypertensive medicaments such as diuretics, beta-blockers, ACE inhibitors and calcium antagonists all indicate a vascular problem which often has a central component. Diuretics act on various parts of the kidney nephron to reduce water and salt reabsorption, reducing preload and cardiac output and, as a consequence, blood pressure. Beta-blockers prevent the stimulatory action of endogenous catecholamines on the heart, again reducing cardiac output and blood pressure. ACE (angiotensin-converting enzyme) inhibitors interfere with the production of angiotensin 2, which is both a powerful vasoconstrictor and triggers release of the hormone aldosterone from the adrenal cortex. As aldosterone promotes water and salt reabsorption from the kidney, drugs that inhibit its release will again reduce preload and cardiac output, so that ACE inhibitors promote a two-pronged attack on blood pressure. Calcium antagonists act by interfering with the process of vascular smooth
Transcutaneous oxygen tension (Tcp02) values of right and left dorsum of the feet were 41 and 47 mmHg, respectively. He had suffered a myocardial infarction and a stroke when 76 and his medication had been changed to digoxin and furosemide (frusemide). When the patient first presented to the clinic, the condition of skin, nails and general tissue viability were unremarkable for someone of his age. Three years later he had suffered a myocardial infarction and a stroke, which suggests possible atherosclerosis in coronary and cerebral arteries. The likelihood of lower limb arteries also being involved is considerable and would account for the low oxygen tension in the skin and the barely palpable pedal pulses. Smoking is a risk factor for atherosclerosis and for strokes. The peripheral oedema and cyanosis were likely to be consequences of cardiac insufficiency following the myocardial infarction, although asymmetry also suggests some peripheral factors at play, i.e, venous incompetency.
muscle contraction, reducing peripheral resistance and so reducing blood pressure.
Symptoms Angina and myocardial infarction
Pain in the chest on exercise or other stress indicates inadequate blood supply to the myocardium. Angina may occur as the result of a previous myocardial infarction (M!) or may be the precursor to an MI. The pain of angina can vary from a mild discomfort to an intense crushing sensation, or a feeling as if the chest is being gripped by a steel band. It may radiate into the left arm, to the back and the throat or even down the right arm. It may settle into a predictable pattern so that the patient will be able to describe the trigger factors and the intensity, duration and frequency of the attacks. More seriously, the attacks may increase in frequency or intensity, when it is termed unstable angina and may be prodromal to an acute heart attack. Unless vigorously treated, a large proportion of patients with unstable angina will go on to develop MI within weeks (Kumar & Clark 1990a). It is important to recognise such situations should they develop, as prompt action is essential.
VASCULAR ASSESSMENT
The chief distinguishing feature of an acute MI as opposed to an angina pectoris attack is that the latter lasts only minutes and is usually relieved within 5 minutes by rest or by sublingual nitroglycerine. Any chest pain that does not ameliorate after both these procedures must be viewed with concern. If after administration of further nitroglycerine the patient still does not obtain relief, emergency services should be called. There are many other causes of chest pain: few closely mimic angina, although indigestion and other gastrointestinal disorders are often confused with angina (Ch. 5). Breathlessness (dyspnoea)
While the most common cause of dyspnoea is physical exertion, it can be associated with cardiac problems. It should be established whether the patient is a smoker or not, since there is a close correlation between smoking and cardiovascular problems. The early stages of heart failure result in metabolic acidosis, which causes compensatory hyperventilation. In ~ater stages, the lungs are congested and ventilatory effort is increased. Difficulty in breathing when supine (orthopnoea) accompanies left ventricular failure (Kumar & Clark 1990b).
Lassitude
One of the main symptoms associated with anaemia is lassitude, with other symptoms depending on the severity and duration of the condition and the particular type of anaemia such as peripheral neuropathy associated with pernicious anaemia or leg ulcers associated with sickle cell anaemia. Although anaemias lead to hypoxia in the tissues, their effects on tissue viability tend to be less severe than those of arterial occlusion since they have no direct effect on supply of nutrients and removal of waste products. However, Blackwell (2001) states 'even mild cases of anemia warrant investigation. Whatever it's cause, ... anemia can signal a life-threatening condition'. In the elderly, anaemia can trigger or exacerbate angina pectoris, claudication or dementia.
91
Observable signs Oedema
Any factor which interferes with the normal process of tissue fluid formation and reabsorption may cause fluid to accumulate in the tissues. This is referred to as oedema, which will be observable in the peripheral tissues as swelling. It can be due to local factors, such as trauma or occluded drainage vessels, or to central factors such as congestive heart failure, where the failure of the left ventricle to produce an adequate cardiac output causes backward pressure through the CVS, in time causing right ventricular failure. Just as left ventricular failure produces oedema in the pulmonary circulation, right ventricular failure results in bilateral peripheral oedema, especially noticeable in the lower limbs (Case history 6.1). An important exacerbating factor is the reninangiotensin-aldosterone system, which is triggered by the low cardiac output and causes renal retention of salt and water, thus imposing an even greater load on the failing heart. Cyanosis
Central cyanosis is the bluish discoloration of lips, tongue and mucous membranes and indicates that arterial blood is inadequately oxygenated. It may be due either to deficiencies in the pump such as a congenital hole in the heart, cardiac failure, or to deficiencies in ventilation such as chronic obstructive airways disease. Severe cardiac and respiratory failure will also cause peripheral cyanosis of toes and feet. Pallor
A generalised pallor, especially noticeable in the face, may indicate anaemia. Spoon-shaped nails (koilonychia)
Lack of iron results in iron-deficiency anaemia, which causes koilonychia of the finger nails and a smooth, red tongue.
92
SYSTEMS EXAMINATION
Clubbing of the nails (hippocratic nails)
Clubbing of the finger nails may be due to subacute infective endocarditis or congenital cyanotic heart disease. It is also associated with a variety of other, primarily respiratory, causes, e.g. bronchial carcinoma. Splinter haemorrhages
These usually appear near the nail margins and are associated with vasculitis (inflammation of small vessels). They may have a local cause such as a digital septic thrombus, or may herald a widespread involvement of arteries of all organs, including coronary, splanchnic and cerebral, as may be seen in severe rheumatoid arthritis. Splinter haemorrhages may also indicate subacute bacterial endocarditis.
Clinical tests Heart rate
This is normally assessed by taking the pulse at the wrist. Arrhythmias are abnormal heart rates and can be physiological or pathological, depending on the cause. Heart rates of less than 60 beats per minute are classified as bradycardia and those over 100 beats per minute as tachycardia. An example of a physiological bradycardia is that seen in trained athletes, whereas the bradycardia due to a complete heart block in the atrioventricular septum is pathological. Physiological arrhythmia may also be associated with respiration and is called sinus arrhythmia, appearing as a tachycardia on inspiration and a bradycardia on expiration. It is more noticeable in young people and is thought to be due to fluctuations in the parasympathetic output to the heart (Ganong 1991), although the fluctuations in thoracic negative pressure may exacerbate the effect through the operation of Starling's law of the heart. Beta.eblockers such as atenolol will induce a bradycardia and thus reduce cardiac output and blood pressure. Such drugs are therefore given as antihypertensives. In contrast, thyroid hormones, if present in excess, increase the affinity of betaI-receptors to catecholamines and so induce
tachycardia, as seen in hyperthyroidism. The tachycardia of exercise illustrates the relationship between heart rate and efficiency, since with up to approximately 180 beats per minute cardiac output also rises; however, at rates greater than this, the diastolic period is so short that the heart cannot fill properly and cardiac output falls. The quality of the pulse should also be noted. Is it irregular, bounding or feeble? The pulse can be graded on a score of 0-4, with 0 representing no pulse and 4 representing a bounding, strong pulse. Irregular or abnormal pulses (arrhythmias) may be physiological (e.g. due to exertion, anxiety, training or age) or may be due to some underlying systemic condition such as thyroid disorders or medication such as beta-blockers. Similarly, a bounding pulse can be due to response to stress, a sign of pyrexia, or can be seen in pathological conditions such as thyrotoxicosis, or in a hypoglycaemic diabetic person. Irregular pulses, i.e. bradycardia, tachycardia or absent pulses, with no apparent explanation should be investigated with Doppler apparatus. Blood pressure
Hypertension is usually asymptomatic unless very severe. Symptoms usually indicate the presence of complications and include headache, nose bleeds and dizziness. It rarely causes oedema. Hypertension is a risk factor for many serious conditions such as MI, left ventricular failure, cerebrovascular accidents, aortic dissection and renal failure. There is a direct correlation between the degree of hypertension and the likelihood of a stroke, so blood pressure values can be one of the most reliable indicators for prognosis of life span; it is, therefore, one of the most useful screening exercises that can be carried out in the clinic. Simple non-pharmacological intervention is usually tried as a first-line method of treatment, unless the condition is severe, with drugs being used only if the situation does not respond or worsens. The pressure in the large arteries will vary during the cardiac cycle. The highest pressure will be at ventricular systole when blood is being forced into the arteries. The pressure at this point
VASCULAR ASSESSMENT
is called the systolic blood pressure. The lowest point is when the heart is relaxed, just before it begins its next contraction. This is called the diastolic pressure. The blood pressure is always written as systolic pressure/diastolic pressure. The value for a healthy adult is 120/80 mmHg (17/11 kPa). Pulse pressure is the difference between the systolic and diastolic pressures and will widen or reduce as either or both pressures change. The value of the systolic and the pulse pressures rises with age due to loss of compliance in the arterial tunica media. The taking of blood pressures by the auscultatory method is a simple technique but requires practice and attention to detail in the procedure (Fig. 6.11). Other methods such as the palpatory method are not considered to be as sensitive. The method was developed using mercury manometers, but increasing awareness of health and safety is seeing the gradual replacement of these by aneuroid manometers, which are not only safer but more user-friendly. Even easier to use are automatic manometers which display the blood pressure and heart rate on a liquid crystal display (LCD) panel although accuracy varies according to the model used. In the manual versions the manometer is connected to a rubber hand pump with a valve and an inflatable cuff and the following procedure should be adopted:
Figure 6.11
93
• The patient should be seated comfortably with one arm flexed at the elbow and resting at heart level on a flat surface. • The brachial pulse should be palpated. • The cuff should be wrapped around the selected arm of the patient, well clear of the brachial pulse point. • The pressure cuff should be inflated until the brachial pulse can no longer be palpated. The value of this pressure should be noted and the pressure released rapidly. • The diaphragm of the stethoscope should be placed on the pulse point and the pressure cuff re-inflated to the same value as previously obtained. Nothing will be heard at this stage. All vessels will be occluded so that no blood can flow through the artery. • The pressure should be released slowly and steadily, watching the needle on the manometer face (or the column of mercury fall). As the pressure falls to the level of the patient's systolic blood pressure a knocking sound will be heard in the stethoscope. At this stage the pressure in the cuff is sufficient to prevent flow of blood during diastole, but not during systole, so that the systolic flow can be heard. The reading of the manometer when the sound is first heard should be noted; this corresponds to the value of systolic blood pressure.
Diagram showing correct position of patient for measuring brachial blood pressure using the auscultatory method.
94
SYSTEMS EXAMINATION
• The pressure should continue to be released. The sounds will first increase then decrease in intensity and finally disappear. At this stage the pressure in the cuff is insufficient to occlude the artery at any stage in the cardiac cycle and this point is taken as the value for the diastolic blood pressure. • The practitioner should ensure that the cuff is deflated completely. The first person to describe this method was Korotkoff and the sounds heard are called Korotkoff sounds. Practice makes perfect! If the readings are not consistent, there are a number of ways in which errors may have been introduced: • The rubber tubing may be perished. • The valve may be faulty. • The cuff may be the wrong size for the diameter of the limb. • The arm may not be at heart level. • The practitioner may not read the values correctly. If in doubt, or if the values are not as expected, the exercise should be repeated, after the patient has had time to relax. Blood pressure values show a Gaussian distribution curve, so the values used to indicate hypertension are somewhat arbitrary. In the UK, hypertension for adults is taken as any systolic value over 160 mmHg and any diastolic value over 95 mmHg. Ideally, readings should be taken on three separate occasions since stress can cause a temporary rise in blood pressure. The most effective way of measuring blood pressure is by a self-monitoring technique. Patients measure their blood pressures at regular intervals throughout the day and an average value is obtained. The upper normal limit is lower in children and higher in the elderly.
Hospital tests These are performed both to confirm diagnosis and to identify the exact site of a problem so that accurate surgical therapy can be performed. Non-invasive Electrocardiogram. The electrical activity of the heart is recorded using limb and chest leads attached to the skin. Many pathologies of the
heart, such as MI or ventricular enlargement in a failing heart, will alter the normal PQRS waveform. Exercise may be used to highlight problems not apparent at rest. Chest X-ray. A standard radiograph of the chest will show such pathologies as enlargement of the heart, calcification of coronary arteries and malignant masses. Phonocardiography. This involves the application of a sensitive microphone to the chest wall, to allow heart sounds and murmurs to be recorded, but is now being superseded by echocardiography. Echocardiography. This uses ultrasound at a frequency of 2.5 MHz to visualise both the heart and the coronary arteries. It can visualise movement of ventricular walls, septum and heart valves (Kapoor & Singh 1993a). Electron beam tomography. A recently developed non-invasive procedure, electron beam tomography has been shown in a recent study to be more sensitive in detecting those patients at high risk of CAD than the more usual procedure of analysis of lipid cholesterol levels (Hecht & Superko 2001). Invasive techniques Blood analysis. Diagnosis of anaemia can be easily confirmed with a full blood count, where the number and volume of the red blood cell is calculated, as is the oxygen content (Ch. 13). Further investigations are then required to establish the cause. Where aplastic anaemia is suspected, a sample of bone marrow is analysed, usually from the sternum. During unstable angina or episodes of MI the ischaemic myocardial cells produce increased amounts of particular enzymes and metabolites, such as cardiac creatine kinase, which peak 24 hours after the attack, so that quantitative analysis of these substances aids diagnosis. Analyses of levels of low-density lipoprotein cholesterol (LDLC) and high-density lipoprotein cholesterol (HDLC) are used as screening processes, especially where a patient is at high risk of CAD, such as those with familial hypercholesterolaemia. Patients with levels of LDLC >130 mg/ dl (3.4 mmol zl) or with levels of
VASCULAR ASSESSMENT ---"--------"----------"-------"-"--"------"-----"-------
HDLC 10.1 indicates increased risk of developing neuropathy. Testing small-diameter fibres Temperature. Two test tubes filled with warm and cool water are preferable to immersing saline sachets in cool and warm water, which quickly lose their temperature differences. Metal rods cooled or warmed in water can also be used. A small cylinder made of two metals with dissimilar conductivities is even easier to transport and use, but is not so readily available in the UK. For research purposes, quantitative instruments to measure temperature perception thresholds using thermode devices (Kalter-Leibovici et al 2001) or thermo-aesthesiometers (van Schie et al 1998) have been used. The latter paper concludes that a combined method, using two simple clinical tests and the more sophisticated apparatus, produced the highest sensitivity (76%). This tests the integrity of the warmth and cold temperature receptors that feed into the anterior part of the anterolateral columns. The nerve fibres involved are narrow diameter A-delta and C fibres. Cutaneous receptors detect absolute values rather than the temperature gradient across the skin. Warmth receptors operate in the range of 30---43°C and cold receptors operate in the range of 35-20°C (Vander et al 1998). Temperatures above 43°C or below 20°C will trigger pain receptors. The skin temperature is usually a few degrees cooler than that of core temperature, i.e.
NEUROLOGICAL ASSESSMENT
between 30 and 35°C, though a greater difference may exist in extremes of environmental temperatures. The temperature of the warm water should be above 35°C and that of the cold water below 30°e. Again, with eyes closed, the patient is asked to state which they find the cooler/warmer from the first or second tube presented. Pain. Disposable Neurotips (Owen Mumford) are best used for this test. The Neurotips have a sharp and a blunt end, but the sharp end cannot pierce the skin. Spring-loaded devices which are designed to deliver a stimulus at a force of 40g are thought to be the safest and most reliable way of testing for pinprick sensitivity (Wareham et al 1997). The use of the sharp end of a patella hammer is not advisable as it may be sharp enough to penetrate the skin and is non-disposable. A hypodermic syringe should not be used as the danger of skin penetration is high. This tests the integrity of the sharp pain pathway, which begins with free nerve endings in the dermis. A-delta fibres travel into the spinal cord and synapse in the dorsal horn. The postsynaptic fibres then cross to the contralateral anterolateral columns which travel up to the brain. Using disposable Neurotips and with eyes closed the patient is asked to state which is sharper, the first or second sensation. The two ends should be presented in random sequence to avoid correct guessing by the anxious-to-please patient. Neuropathy does not always mean absence of pain, as is witnessed by diabetic patients with neuropathy who can experience a period of intense pain (Boulton 2000). There are certain perceived wisdoms concerning sensory testing on diabetic patients which the busy practitioner may use to justify using only one of the above methods: • vibration sensation is the first modality to deteriorate • the presence of neuropathy as indicated by failure to detect the 109 monofilament implies neuropathy of all nerve fibres in that limb. There is no conclusive evidence to support either of these statements. Indeed Winkler et al (2000) have reported the existence of a subgroup
143
of type 1 diabetic neuropathy patients who suffer from autonomic symptoms severe enough to warrant treatment, such as severe bladder or gastroparesis, orthostatic hypotension and diabetic diarrhoea associated with a selective smallfibre sensory and autonomic loss with relatively preserved large-fibre sensory modalities such as vibration and touch-pressure sensation. Whether either or both of the above statements can be applied to patients without diabetes is even less certain. A study by Nakayama et al (1998) on rats showed that small-diameter, unmyelinated nerve fibres decrease in number with ageing whereas larger-diameter fibres maintain both conduction ability and numbers. In the absence of solid evidence to the contrary, it would seem advisable to carry out sensory testing on both small and large fibres. However, any testing is better than none. In research studies, a range of sensory tests have been used to calculate a neuropathy disability score (NDS). For further discussion of peripheral neuropathy assessment in patients with diabetes mellitus see Boulton et al 1998, Young & Matthews 1998 and Chapter 17. Tinel's sign. This helps in the diagnosis of nerve compression. Palpating the nerve, or tapping it with a patellar hammer, at the site of compression will often elicit an abnormal sensation distally, but it can also follow the proximal distribution of the nerve. Usually the sensation is paraesthesia (tingling, burning) or is like an electric shock. Tinel's sign can be used to assess for compression of the medial nerve at the wrist or the posterior tibial nerve at the ankle (carpal and tarsal tunnel syndromes). However, no clinical tests for carpal and tarsal tunnel syndromes are entirely reliable (Golding et al 1986), so that the suspicion of such a condition needs to be confirmed by nerve conduction tests (see Hospital tests). Referred pain. Entrapment of a spinal nerve may lead to paraesthesia, pain and weakness of muscles in the lower limb. Normally when pressure is applied to a site of pain, the pain becomes worse. However, with referred pain the level of pain stays about the same. A suspected entrapment of the sciatic nerve usually leads to pain when the affected leg is raised while the patient lies in a supine position.
144
SYSTEMS EXAMINATION
Hospital tests Nerve conduction test. Sensory nerve conduction velocities are measured by placing stimulating electrodes on the skin over the nerve to be tested. Recording electrodes, either skin or needle electrodes, are placed either proximally for orthodromic stimulation or distally for antidromic stimulation. The latter gives more consistent results. The lower limit of normal sensory conduction velocities in the lower limb is around 35 m/ s. Values are less than those for the upper limb. A slowing of conduction velocity may be due to a variety of causes (Matthews & Arnold 1991):
• ageing • damage to the cell body as in herpes zoster (shingles) • nerve axon damage as in compression due to a spinal tumour, a slipped disc or tarsal! carpal tunnel syndrome • demyelinisation as seen in Guillain-Barre syndrome. Amplitude of the action potentials and latency are also measured. For a brief discussion of possible findings, see section on motor nerve conduction tests. Nerve biopsy. This can be carried out on sensory, motor and autonomic nerves. A small sample of tissue is removed, using a needle, cone or, if surgery is being performed, a scalpel. The tissue is examined histologically and its interpretation requires great expertise. Characteristics such as a thickened basement membrane, scarring of the myelin sheath, etc., can be identified. Biopsies are carried out where another laboratory test is inconclusive or where no other diagnostic test exists for the suspected condition.
ASSESSMENT OF LOWER LIMB MOTOR FUNCTION If the motor system is functioning normally
muscles should display a resting tone, show good muscle power on active contraction and be able to move against resistance (Ch. 8). The lower limb reflexes, patella and Achilles, should also show a normal response. Reflex path-
ways involve both an afferent and an efferent component and therefore a deficit in either component would be expected to have an observable effect on the response, as would abnormal influences by higher centres on the LMN. Reflex responses can be graded as follows (Fuller 1993a): 3+ == clonus 2+ == increased 1+ == normal +/ - == obtainable with reinforcement o == absent. Values of 2 and above suggest UMN lesions, values of below 1 suggest LMN lesions, peripheral sensory nerve or muscle damage. The patellar reflex. This tests the integrity of the spinal reflex pathway (L3, L4) and demonstrates descending influences on the ventral horn cell. It is important that the limb being tested is as relaxed as possible. The patient should sit sideways on the examination couch with the feet clearing the ground. The practitioner can gently push the leg to be tested, which should swing freely in response. A gentle tap on the patellar tendon with the hammer should elicit a knee jerk. If the leg is not relaxed, the patient should clasp both hands around the other knee and pull (Jedrassik manoeuvre). This releases spinal influence and allows the leg to relax. The test should be undertaken on both legs. The Achilles reflex. This tests the spinal reflex pathway (51, 52). The response is best elicited if the foot of the patient is slightly dorsiflexed by applying gentle pressure to the plantar surface of the forefoot with one hand and tapping the Achilles tendon while the pressure is maintained. The patient can either sit on a couch, with legs extended and the limb being tested crossed over the other, or kneel on a chair, with the foot to be tested hanging slightly over the edge of the chair. In a healthy young adult the forefoot will gently plantarflex. In an elderly person no visible movement may be seen, but a very slight plantarflexion will be felt against the practitioner's hand. Lower limb motor dysfunction can occur as a result of damage to upper motor neurones, lower motor neurones, peripheral nerves or muscles.
NEUROLOGICAL ASSESSMENT
Upper motor neurone lesions Upper motor neurone (UMN) lesions are due to damage occurring anywhere between the cortex and L1 in the spinal cord. Since the spinal cord ends at level L1, lesions below this level will not produce UMN signs. Conditions which can lead to UMN signs are listed in Table 7.14. Although a specific area of the frontal lobes (precentral gyrus) is designated the primary motor cortex (see Fig. 7.12), many neurones from other areas of the cortex are also involved in planning and initiating conscious movement and so can also be called upper motor neurones. This includes neurones of both descending tracts. Damage to the descending tracts will produce the same effects as damage to the neurones themselves. Observation
Damage to the corticospinal neurones and tracts will result in contralateral loss of skilled movements. Lack of movement will in turn eventually lead to a form of muscle atrophy known as disuse atrophy. Damage to the multineuronal pathway causes release of inhibition on the LMNs in the spinal cord, especially those which innervate the antigravity muscles, producing the effect most commonly associated with UMN lesions, that of spasticity or stiffness in the limbs. Gait. Observation of the patient's gait is an important part of the assessment for UMN lesions. In the lower limb the effect is extension at Table 7.14
Conditions associated with UMN signs
• Cerebral palsy due to anoxia at birth • Cerebral vascular accidents Brain injury • Friedreich's ataxia Spinal injury Brain or spinal tumours Amyotrophic lateral sclerosis (motor neurone disease) • Vitamin B12 deficiency • Multiple (disseminated) sclerosis • Later stages of syringomyelia
145
the hip and knee, with plantarflexion and inversion of the foot. If the effect is unilateral, the person is described as hemiplegic. The inability to flex the knee and hip leads to a circumductory gait, with the lateral border of the forefoot and toes often scraping the ground. If both sides are affected the person is paraplegic and the gait is described as a scissor gait, with the knees adducted and feet abducted. Walking aids such as Zimmer frames are essential. Clinical tests Clasp-knife spasticity. The affected limb will be initially stiff to passive stretch, but if gentle stretch is continued, the limb may suddenly relax, rather like the opening of a clasp-knife. This is due to a length-dependent inhibition of the stretch reflex (see Fig. 7.16). Tendon reflexes. Due to the reduced inhibition by the multineuronal tracts, the alpha LMNs responsible for the contraction of extrafusal fibres are hyperexcited. This results in exaggerated patella and ankle tendon reflexes and clonus - increased rhythmic contractions elicited at the ankle or patella by causing brisk stretch of the muscles. More than three contractions as a result of testing the patella or Achilles reflex is indicative of UMN damage (Fuller 1993b). Plantar reflex. Damage to the corticospinal neurones or their axons has another effect that is clinically detectable, the so-called plantar reflex or Babinski sign. It has been suggested that the abnormal reflex, a dorsiflexing big toe, is due to release of a spinal inhibitory reflex (Van Gijn 1975). The plantar surface of the foot is stroked firmly and briskly from the posterolateral border of the heel to the hallux as shown in Figure 7.17. The normal response is a slight plantarflexion of the hallux and lesser toes, although no response is also often seen, especially in the elderly where the sensory pathway may be affected. In patients with corticospinal tract dysfunction, the hallux will extend (dorsiflexion of the hallux) and the lesser toes may fan out. This is the extensor response, sometimes referred to as a positive Babinski response. However, the normal response does not become established until the
146
SYSTEMS EXAMINATION
will be on the same side, below the level of the lesion (Case history 7.1). /
Hospital tests
l
The use of tests to diagnose UMN lesions will vary according to the suspected cause. For example, brain scans are indicated if a CVA is suspected, whereas a spinal radiograph would be used if a tumour of the spine was suspected.
Lower motor neurone lesions
A
\
B
,
e
Figure 7.17 The Babinski response A. Eliciting the response B. Flexor response (normal response) - toes plantarflex e. Extensor response (positive Babinski sign) - toes dorsiflex.
person has learnt to walk and so an extensor response is quite normal in babies. It is important not to rely only on this test for diagnosis of UMN lesions as it is easy to elicit a pain withdrawal response which may appear similar to an extensor response. The rest of the clinical picture should also suggest UMN lesions. Muscle tone. Due to the release of spinal inhibition in UMN conditions, the LMNs will be in a hyperexcited state and so will be firing more frequently. This will result in greater muscle 'tone' and the affected muscle will feel very firm or tense. Any condition which causes damage to the UMNs or their descending tracts can produce UMN signs. If the cortex is affected, the effects will occur on the contralateral side of the body, and if the lesion is in the spinal cord, the effects
As the lower motor neurone cell body, its efferent fibres, the neuromuscular junction and the 10-600 skeletal muscle fibres it innervates all act as a coordinated whole, damage to any part of this motor unit will produce similar effects of weakness (paresis) or complete loss of function (paralysis) and reduced or absent reflexes. Diseases principally affecting the muscles are called myopathies, but this can be confusing as often the cause is lesions in the LMN which have given rise to atrophy of the muscle. Therefore, assessment of all parts of the motor unit will be considered in this section. For classification of myopathies, see Table 7.15. Since LMNs or their spinal nerves exit at all segments of the spinal cord, LMN symptoms can be seen as a result of damage to any segment from
Case history 7.1 A 70-year-old female Caucasian presented to the clinic complaining of excessive wear on the lateral border of the left shoe and a corn on the dorsum of the fifth toe. The patient walked with a stick and had a slow, circumducted gait; the left arm was held in a flexed position. Neurological assessment revealed normal tendon reflexes and muscle power in the right leg but exaggerated tendon reflexes and an extensor plantar response (positive Babinski sign), clonic spasm of the muscles and signs of muscle atrophy in the left leg. Diagnosis: History taking revealed the patient had suffered a major eVA, which had affected the right cortex. The clinical features were consistent with the history. Fortunately for the patient she was righthanded so her speech was not affected and she was still able to feed herself and write.
NEUROLOGICAL ASSESSMENT
Table 7.15
147
Classification of myopathies
Classification
Descriptor
Inherited
Muscular dystrophies (at present untreatable) Duchenne's - X-linked recessive condition. Commonest and most serious of the inherited dystrophies. Affects males, females are carriers. Onset before age 10 years. Weakness in proximal and girdle muscles of lower limb first, later upper limbs also. Hypertrophy and later fatty infiltration (pseudohypertrophy) of calf muscles. Cardiac muscle also affected. See ele vated levels of serum phosphokinase. Death from respiratory failure usual between 20 and 30 years Becker's - X-linked recessive condition. A more benign variety of the above Dystrophia myotonica - autosomal dominant condition. Gene located on chromosome 19. Insidious onset, usually between 20 and 50 years, but can be present earlier. Progressive weakness and wasting of distal as well as proximal limb muscles, facial and sternomastoids. Cardiomyopathy, cataracts and frontal baldness also common. Myotonia is failure of muscle to relax immediately after contraction. Patient cannot open hand quickly after making a fist. Faulty gene leads to defective chloride ion transport, resulting in membrane hyperexcitability Facio-scapulo-humeral-autosomal dominant condition - benign, often asymptomatic. Wasting and weakness of facial, scapular and humeral muscles mean patient has difficulty in whistling, heavy lifting, etc., as well as scapula in abnormal position Limb girdle - variable inheritance (may be treatable, depending on cause). Several causes: specific biochemical defect, benign form of motor neurone disease, polymyositis, hormonal and metabolic disease
Biochemical defect
McArdle's syndrome. Abnormality of glycogen metabolism due to deficiency of muscle phosphorylase. Patient suffers from fatigue, cramps and muscle spasm. Malignant hyperpyrexia. No muscle wastage or weakness. Symptoms occur during or immediately after administration of a general anaesthetic, especially if halothane or the muscle relaxant suxamethonium chloride is given. Defect in calcium metabolism gives rise to prolonged muscle contraction, in turn raising body temperature. Fatal in 50% of cases
Acquired inflammatory
Polymyositis-autoimmune disease. Infiltration of monocytes and muscle necrosis. Weakness of proximal limb, trunk and neck muscles. Patient has difficulty raising hands above head, getting up out of low chairs and bath. May be associated pain on muscular exertion Dermatomyositis. As above, with additional involvement of skin of face and hands, with erythematous rash
Non-inflammatory
Secondary to high-dose steroids and thyrotoxicosis. These are the most usual causes, but can also be associated with alcoholism, Cushing's disease, Addison's disease, acromegaly, osteomalacia and malignancy. See weakness of proximal limb muscles and shoulder girdle. Trunk may also be involved
C1 to 55. However, due to the anatomy of the spinal cord any damage to the cord from L2 will only result in an LMN lesion. It is possible to see a combination of UMN and LMN symptoms if the lesion is between C1 and LI, e.g. syringomyelia. The conditions that can lead to lower motor neurone lesions are listed in Table 7.16. Observation If the pathway is interrupted or damaged in any
way, either at the level of the cell body or along
Table 7.16 Conditions associated with lower motor neurone lesions
• Poliomyelitis • Injury to lower motor neurone and/or peripheral nerve • Motor neurone disease Syringomyelia Vitamin B12 deficiency Cord compression/lesion (Brown-Sequard syndrome) Spina bifida • Charcot-Marie-Tooth disease
148
SYSTEMS EXAMINATION
Case history 7.2
Case history 7.3
A 54-year-old male Caucasian first presented to the clinic complaining of corns and callus under the metatarsal heads of both feet. He was unable to bend down to cut his toe nails. A vascular assessment revealed weak pulses in both feet, with the right foot being cold. A neurological assessment revealed dimished reflexes in the right leg and absence of vibration sense in the right foot. Two-point discrimination was 2 ern in the left foot and 10 cm in the right foot. Orthopaedic examination showed a leg length discrepancy of 2.5 ern, the right leg being the shorter and having developed a functional equinus at the ankle. Muscle wastage was apparent in the lower limb of the right side. The patient walked with a limp. Diagnosis: The signs and symptoms are all consistent with poliomyelitis. The patient had contracted the virus when a child. The lower motor neurones of the right side of the spinal cord at the level of the lumbar plexi had been affected.
A 52-year-old Caucasian female presented to the clinic with plantar callus and fissuring, which had arisen following plantar fasciotomy to correct 'clubbed feet'. The patient stated that she had been born with normal feet, but by the time she was 6 years old she could not run or jump properly and by the time she was an adolescent her feet had become high-arched and inverted. She had noticed a gradual weakness in her arms and legs and on one accasion, when 41 years old, she had almost dropped a baby while working as a nursing auxiliary. This incident had caused her to be sent for a neurological examination which revealed slowed motor nerve conduction velocities. She had a recent history of several falls, with her ankle 'going over'. She also complained of aching joints in the feet, knees and hips. Her 27-year-old son was similarly affected. Neurological examination showed all sensory perception except vibration to be normal, but reflexes were absent. Muscle power was reduced in all limbs and muscle wasting of hands, feet and calf muscles was noted. Orthopaedic examination showed reduced dorsiflexion and eversion, with a pes-cavus-typa foot and high-stepping gait. Diagnosis: The patient suffered from Charcot-Marie-Tooth disease, also known as peroneal muscle atrophy. It is an inherited peripheral neuropathy and exists in more than one form, the two most common forms being autosomal dominant.
its axon, then the impulse cannot reach the muscle. The result will be weakness (paresis) or flaccid paralysis, depending on the site and extent of the damage. The sites of damage may involve: • lower motor neurone, e.g. poliomyelitis virus (Case history 7.2) • peripheral axon, e.g. diabetes mellitus • neuromuscular junction, e.g. destruction of cholinergic receptors of the skeletal muscle as in myasthenia gravis. Myopathies will also produce weakness or paralysis, even if the lower motor neurone is intact. In contrast to UMN lesions, which affect particular movements, LMN lesions and myopathies affect particular muscles (Case history 7.3). For example, if the tibialis anterior nerve is affected the anterior tibial muscle is unable to control deceleration of dorsiflexion at the ankle in gait, producing a characteristic slapping gait (Root et al1977). Nerve impulses are essential to the health of the muscle, so that lack of impulses leads to much more rapid atrophy of muscle, skin and other soft tissue than seen in UMN lesions. This is known as denervation atrophy. In addition, the denervated muscle becomes highly sensitive to
very small amounts of neurotransmitter (acetylcholine), possibly due to upregulation of receptors. This results in a quivering of the muscle (fasciculation), seen on an electromyogram as fibrillation. This effect will not be seen if the lesion is in the muscle itself. Clinical tests Muscle power: Muscle power can be graded according to the Medical Research Council scale (Fuller 1993c) as follows: 5 = normal power 4+ = submaximal movement against resistance 4 = moderate movement against resistance 4- = slight movement against resistance 3 = moves against gravity but not resistance 2 = moves with gravity eliminated 1 = flicker a = no movement. A reduced strength of contraction suggests paresis or paralysis.
NEUROLOGICAL ASSESSMENT
Fatiguability. If the site of the lesion is the neuromuscular junction, the muscle will show a sliding decrease in response or fatiguability as seen in myasthenia gravis. The acetylcholine receptors are destroyed in an autoimmune attack and although the first quanta of neurotransmitter can diffuse to remaining receptors, subsequent release of neurotransmitter is less and less likely to make contact and so the response fades. The muscle cells are able to replace the receptors but the autoimmune attack will strike again, in the same or different muscles. Muscle tone. In the skeletal muscles of a healthy person there will always be some motor units firing, which means that the muscle will feel firm. This is referred to as the 'tone' of the muscle. In LMN or muscle damage, the muscle will feel flabby, because of loss of this tone. Tendon reflexes. Reflexes will be weak or absent, because of interruption of the final common pathway. A single reduced or absent reflex suggests mononeuropathy or radiculopathy. A reduction or absence of all lower limb reflexes suggests polyradiculopathy, cauda equina lesions, peripheral polyneuropathy or a myopathy. In the latter there will be no sensory deficit.
Hospital tests
Again, the tests selected vary according to the suspected cause. For example, if diabetic polyneuropathy is suspected, the diagnosis could be confirmed by a combination of sensory testing, nerve conduction tests and blood glucose measurements. Nerve conduction. To measure motor conduction velocities the stimulating electrode is placed along the path of the nerve and the recording electrode is placed over the belly of the muscle. Amplitude and duration of the action potential are also recorded. The lower limit of normal conduction velocities in the lower limb is 40 m/ s. Nerve conduction tests, whether sensory, motor or mixed nerve, do not give definitive diagnoses but help to confirm diagnosis: e.g. by comparing the affected side with the healthy side
149
as in diagnosing tarsal tunnel syndrome (Galardi et al 1994) or by distinguishing between axonal degeneration and segmental demyelination, the two chief pathological processes occurring in peripheral nerve diseases. The distinguishing characteristics are shown below. Axonal degeneration, e.g. the polyneuropathies of diabetes mellitus, alcoholism, toxicity due to heavy metals, nerve entrapment and Friedreich's ataxia (Zouri et al 1998): • see clinical changes first (weakness, numbness, atrophy) • slowing of nerve conduction velocities and loss of large fibres • reduction in action potential amplitude • more prominent distally than proximally (longest fibres affected first) • fibrillation seen on electromyograph. Segmental demyelination, e.g. vasculitis of rheumatoid arthritis (acquired, chronic), Guillain-Barre syndrome (acquired, acute/ chronic), Charcot-Marie-Tooth disease/peroneal muscular atrophy/hereditary motor and sensory neuropathy (inherited, chronic): • electrophysiological changes seen first • dramatic fall in nerve conduction velocities, maybe even total conduction block • worsens proximally. Charcot-Marie-Tooth disease is interesting because two subtypes have been identified: HMSN type I, which shows primarily segmental demyelination, and HMSN type II, which shows mainly axonal degeneration (McLeod & Lance 1989b). Electromyography. This uses a needle electrode inserted into the muscle to show the electrical activity of the muscle in response to an electrical stimulus. Abnormal results are detected in dysfunction of motor nerves, neuromuscular junction lesions and in myopathies (Matthews & Arnold 1991). Electromyography is the only means of electrophysiological testing for myopathies: • if due to motor nerve denervation (e.g. poliomyelitis), will see reduced recruitment,
150
SYSTEMS EXAMINATION
Table 7.17
Differences between upper motor neurone and lower motor neurone lesions
Upper motor neurone
Lower motor neurone
Exaggerated tendon reflexes
Loss of tendon reflexes
Extensor plantar response (positive Babinski sign)
Flexor plantar response (negative Babinski sign)
Loss of abdominal reflex
Normal abdominal reflex
Normal electrical excitability of muscle
Fasciculation (fibrillation seen on EMG)
Some muscle wasting over a period of time due to lack of use
Marked muscle wasting occurs relatively quickly
Increase in muscle tone (clonus)
Flaccid muscles (lack of tone)
Whole limb affected
Certain muscle groups affected depending on site of damage; deformity due to contracture of antagonists
fibrillation, then a reduction in nerve action potential amplitude • if due to changes at the neuromuscular junction (e.g. myasthenia gravis), will see a reduction in recruitment • if due to muscle disease (e.g. Duchenne's muscular dystrophy), will see spike potentials on the electromyograph.
reflexes necessary for accurate movement. The basal ganglia also play an important part in the coordination of movement. Damage to these parts of the nervous system may have an effect on gait and coordination. Conditions that may affect coordination and proprioception function are listed in Table 7.18.
Tests may be performed that are specific to particular conditions, such as detection of the presence of antibodies to cholinergic receptors in myasthenia gravis. Nerve and muscle biopsies. These are obtained in an identical manner to those described for sensory nerve biopsies. Histological examination of nerve and muscle tissue will show structural abnormalities, and biochemical tests will detect enzyme dysfunction: e.g. in distinguishing Duchenne's muscular dystrophy from the treatable connective tissue disease of polymyositis, which also shows muscle weakness and atrophy of limb girdles. The differences between UMN and LMN lesions are summarised in Table 7.17.
Observation
ASSESSMENT OF COORDINATION/PROPRIOCEPTION FUNCTION The receptors in the muscles, joints and tendons all feed position sense information to the cerebellum and cortex. In turn, the cerebellum and the cortex bring about vital postural reflexes and
Careful observation of motor activity can give an indication of a deficit in posture, balance or coordination; for example, a stamping gait may be due to loss of proprioception as occurs in
Table 7.18
Conditions that may result in poor coordination
Part
Conditions
Cerebellum
Tumour Multiple sclerosis Arnold-Chiari malformation Friedreich's ataxia Other hereditary spinocerebellar ataxias Hypothyroidism Repeated head trauma as in boxing
Basal ganglia
Parkinsonism Huntington's chorea Wilson's disease Sydenham's chorea
Ascending pathways
Subacute combined degeneration of the spinal cord Guillain-Barre syndrome Tabes dorsalis Alcoholism
NEUROLOGICAL ASSESSMENT
tabes dorsalis, where the ascending tracts in the dorsal columns degenerate. The patient will not know where his body is in space and so lifts his legs much higher than necessary to clear the ground. The patient will also be unaware of when his foot is about to make ground contact and so stamps the foot down. This has the advantage of stimulating pressure receptors proximally, as vibrations from the foot travel up the leg and so provide much needed information to the brain. The cerebellum has modifying influences on the UMNs in the cortex and on brain-stem nuclei. It receives rich proprioceptive information and adjusts the activity of the UMNs to ensure that the actual action and intended action are matched. The cerebellum is essential for smooth, accurate movement and posture and balance. Dysfunction of the cerebellum or of its afferent and efferent tracts produces characteristic effects that are easily observable. Dysarthria. Here cerebellar dysfunction affects the speech muscles and produces a scanning speech, with inappropriate syllabic stress and volume. Dysdiadochokinesia. This is where actions are no longer smooth, continuous movements, but are broken down into their component parts, producing clumsy, jerky actions. Tremor. The tremor associated with cerebellar defect is due to the dysfunction of the stretch reflex and is an intention tremor, i.e. one which increases in amplitude as the person tries to carry out any tasks with the affected limb. The tremor disappears at rest. Gait. If maintenance of balance is upset, the patient will feel unsteady and adopt a wide base of gait. As voluntary movement is also affected, the gait will be clumsy or staggering, as if drunk. Such gait is described as ataxic. The patient may complain of deviating to one side, which suggests the dysfunction is limited to that hemisphere. Basal ganglia. Although the basal ganglia also have a modifying role on voluntary movement, the effects of their dysfunction is quite different from that of the cerebellum. Damage to the basal ganglia produces either a poverty of movement
151
(hypo /bradykinesia) as seen in Parkinson's disease, or jerky writhing movements (choreoathetosis) as seen in the inherited disease of Huntington's chorea (Case history 7.4) or the benign and brief effects of Sydenham's chorea, associated with rheumatic fever.
Clinical tests Proprioception in joints. To test proprioception distally, the practitioner holds the sides of the hallux between forefinger and thumb. While the patient's eyes are shut, the toe is moved up and down and the patient should be able to state the final position of the toe. The sides of the hallux are held rather than the dorsal and plantar surfaces, to avoid additional pressure information being generated. This information travels from receptors in joints in the largest-diameter, fastest nerve fibres of the A-alpha class into the spinal cord, up to the cerebellum in the ipsilateral spinocerebellar tracts and to the conscious cortex in the dorsal columns. A positive result shows that the pathway to the cortex is intact. An inability to give the correct responses would be seen in conditions such as tabes dorsalis. Romberg's sign. This test can be used to confirm proprioceptive disturbance in the dorsal columns or peripheral nerves (Fuller 1993d).
Case history 7.4 A 30-year-old Caucasian male attended the clinic complaining of sore corns. Questioning revealed that he was mentally handicapped. Examination showed warm, hyperhidrotic feet with a poor skin condition and fibrous lesions on the plantar aspect of the feet. The left foot had marked pes cavus deformity. The gait revealed limping and shuffling with excessive arm movement in order to maintain balance. Over a period of a few years further mental and physical deterioration became apparent. The patient's brother was similarly affected and so apparently had been their father. Diagnosis: A diagnosis of Huntington's chorea was made. This disease is inherited as an autosomal condition with complete penetration and late onset, and is characterised by progressive chorea and dementia.
152
SYSTEMS EXAMINATION
Patients are observed standing with feet together and eyes open and then closed. If patients are unable to maintain balance with eyes open, this suggests either a cerebellar or a vestibular defect and if the patients rock backwards and forwards with eyes open a cerebellar defect could be the cause. In such cases this is not a positive Romberg's sign and Romberg's test cannot be performed. Closing the eyes will deprive the patients of visual information, so that the brain has to rely on proprioceptive input: if this is not being transmitted, the patients will sway and find it difficult to keep balance. The practitioner must be ready to catch the patient. A positive Romberg's sign could be due to cord compression, tabes dorsalis, vitamin B12 deficiency or degenerative spinal cord disease. Nystagmus. This is rapid eye movements due to vestibular dysfunction and can be elicited by asking the patient to make a sudden rapid head movement. Its presence indicates a cerebellar lesion. Heel-shin test. The patient is asked to slide the heel of one leg straight down the shin of the other. Patients with cerebellar dysfunction are often unable to do this because of lack of coordination and the heel will follow a wavy path down the other leg. Heel-toe test. The patient is asked to walk in a straight line heel to toe. Patients with cerebellar dysfunction will stagger about the midline, but it must be remembered that there are many other causes of an unsteady gait, especially in the elderly. Finger-nose test. The patient is asked to stand comfortably and then, with eyes shut and one arm outstretched, to bring his fingertip to the nose. Repeat for the other arm. Cerebellar dysfunction will cause the patient to overshoot (hypermetria) or undershoot (hypometria) and miss the nose. Muscle tone. This will be reduced in the affected limbs. Tendon reflexes. These may be unusually sustained, because of the oscillations of an abnormal stretch reflex, but should not be exaggerated. Occasionally, a weak response can be seen in cerebellar syndromes.
Parkinson's disease
This is the commonest extrapyramidal disease and is due to depletion of dopaminergic neurones in the substantia nigra, which project to the caudate nucleus. The most troublesome effect is hypo/bradykinesia, which results in the patient having great difficulty initiating or stopping movement (Case history 7.5). Rest tremor and rigidity are also features. If the hand is affected the tremor may cause the patient to move inde~ finger and thumb in a 'pill-rolling' movement. The patient may show a mask-like face, and speak in a soft voice. Micrographia (small handwriting) is also a characteristic. The antigravity muscles are affected, producing a stooped posture with knees flexed, so that the patient's centre of gravity is no longer over the base of gait. This causes the festination seen in gait, where the patient has to move more and more quickly to avoid falling forward. Gait also tends to be shuffling, with poor heel-ground contact - 'marche ii petits pas'. The tendon reflexes are unaffected. There is a general resistance to passive stretch, described as 'lead-pipe rigidity'. It may show a superimposed intermittent release of the resistance producing a series of jerks, the so-called 'cogwheel' effect.
Case history 7.5 A 65-year-old female Caucasian presented to the clinic requesting nail care. On examination her nails were found to be long, thickened and mycotic and a variety of dorsal, apical and interdigital lesions were present. The patient could appreciate temperature, light touch and pressure and reflexes were normal, but she was very confused and nervous, so that communication was difficult. A full orthopaedic assessment could not be carried out because of the patient's inability to relax her legs and feet. Ankle dorsiflexion was limited and the feet adopted a varus position. Most of the toes showed retraction deformities. Movements were hypokinetic and gait was stooped and shufftinq. There was a minor rest tremor in the right arm. Diagnosis: The symptoms are consistent with Parki.n.son's ~isease. This is a progressive idiopathic condition which gradually affects all limbs. Mental confusion/dementia is not always present.
NEUROLOGICAL ASSESSMENT
In a patient with Parkinson's disease, there is no habituation with the glabellar tap reflex. The glabellar tap reflex involves the practitioner gently, slowly and repeatedly tapping the forehead of the patient between the eyes. In a healthy person, the first tap or two will elicit the eyeblink reflex, but this will rapidly habituate. The frequency of the tremor may be measured via hospital tests but usually the above clinical tests and a positive response to drug therapy will be sufficient to confirm the diagnosis of Parkinson's disease.
ASSESSMENT OF AUTONOMIC FUNCTION As explained earlier, the autonomic nerves innervate the viscera and internal structures such as blood vessels, since they enable the nervous system to maintain homeostasis (see Fig. 7.9). Medical history may reveal abnormalities of bowel and bladder function.
Observation There will be various signs which would suggest autonomic neuropathy such as abnormal sudomotor responses in the skin and abnormal cardiovascular responses in the functioning of the heart and peripheral blood vessels (Faris 1991). Sudomotor neuropathy usually leads to an absence of sweating and a dry skin, although it may produce hyperhidrosis. Vasomotor neuropathy usually produces a warm red skin and an absence of vasoconstriction in response to cold although it may occasionally produce a prolonged vasoconstriction. It may also lead to postural hypotension. Neuropathy of nerves to the cardiac pacemaker tissue may lead to failure of the heart to respond appropriately to the demands of the body, e.g. an absence of tachycardia in response to exercise.
Clinical tests Heart rate. The pulse is taken while the patient is in a supine position and repeated when an
153
upright posture is adopted. The normal response is an increase in heart rate of greater than 11 beats per minute. A loss of response suggests parasympathetic abnormality. Blood pressure. Repeat the above test measuring blood pressure in the two positions. The systolic blood pressure should fall on standing by approximately 30 mmHg and the diastolic pressure by about 15 mmHg. An increased drop suggests sympathetic abnormality. Failure of the cardiovascular system to compensate for postural effects can lead to postural syncope. Valsalva manoeuvre. This is not advisable if there is evidence of proliferative retinopathy. The patient is asked to take a deep breath and exhale against a closed glottis for 10-15 seconds and then breathe normally. The pulse rate is taken during the Valsalva manoeuvre and on release. Heart rate should increase during the manoeuvre and fall on release. No increase during the manoeuvre suggests sympathetic abnormality and no decrease on release suggests parasympathetic abnormality. These tests reveal abnormal responses of the baroreceptor reflex, which implicates defects in innervation of the cardiac pacemaker tissue rather than peripheral autonomic neuropathy, for which there are no clinical tests. Certain signs may suggest peripheral autonomic (sympathetic) neuropathy: • a dry skin due to failure of sudomotor nerves • a warm foot due to lack of arterial vasoconstriction • engorged dorsal veins, due to lack of venous vasoconstriction. Signs of parasympathetic neuropathy are disorders of bowel and bladder function and impotence. The condition commonly associated with autonomic neuropathy is diabetes mellitus, where the foot will often appear red and feel dry and warm. There may be coexistent neuropathy of other small fibres such as pain and temperature fibres (A-delta and C), as well as large-fibre (A-alpha and A-beta) involvement, giving rise to the picture of a typical neuropathic foot (Ch, 17). Less common conditions exhibiting
154
SYSTEMS EXAMINATION
autonomic neuropathy are Cuillain-Barre syndrome, amyloidosis and congenital autonomic failure. It should be remembered that other conditions, such as infection and anaemia, and certain drugs, such as beta-blockers, can also affect the cardiovascular system and may give a false-positive result.
Case history 7.6 A 47-year-old male Caucasian was referred to the clinic with a small ulcer which had existed for 6 months beneath his right heel. When 29 years old, he had visited Nigeria where he had contracted schistosomiasis with resultant paraparesis from his lower abdomen downwards. Since then he had suffered repeated ulceration of both feet. The present ulcer was covered with dense callus which when debrided revealed a lesion 15 mm in diameter and 8 mm deep. Its border was surrounded by macerated callus. A vascular assessment showed no remarkable features, all tests indicating a good blood supply to the foot. The neurological assessment revealed absent reflexes, lack of appreciation of all senses and constant 'pins and needles' sensation around his hips and legs. The skin of the feet was dry. The patient used a walking stick to support his right leg and walked with an abductory gait to achieve ground clearance as the right foot could not dorsiflex. The right leg showed wasting of the triceps surae. Diagnosis: A diagnosis was made of neuropathic ulcer associated with peripheral sensory, motor and autonomic neuropathy due to damage in the spinal cord caused by the parasitic blood fluke Schistosoma haematobium.
SUMMARY This chapter has considered the assessment of the various components on the nervous system. However, as stated earlier, it is important to remember that a number of conditions affect more than one part. Those conditions that result in damage to more than one part of the nervous system are summarised in Table 7.19. It is essential that all parts of the nervous system are assessed in order that the practitioner may acquire a full picture of neurological function (Case history 7.6). A summary of the tests discussed and their interpretation is shown in Table 7.20. Table 7.19 Conditions that affect more than one part of the nervous system Condition
Parts affected
Diabetes mellitus
Sensory, motor (LMN) and autonomic
Motor neurone disease
LMN and UMN
Spina bifida
LMN and sensory
Syringomyelia
Sensory, LMN and UMN
Vitamin B 12 deficiency
Sensory, LMN and UMN
Multiple sclerosis
Sensory and UMN
Cord compression/lesion
Sensory, LMN and UMN
Guillain-Barre syndrome
LMN, sensory and autonomic
Charcot-Marie-Tooth disease
Mainly LMN but possible sensory
Nerve injuries
Depends upon site, may result in LMN, UMN, sensory or autonomic
REFERENCES Booth J, Young M 2000 Testing the reliability of 10 g monofilaments. Diabetic Medicine 17: S74 Boulton A J M (ed) 2000 The pathway to ulceration. In: Boulton A J M, Connor H, Cavanagh P R (eds) The foot in diabetes, 3rd edn. J Wiley, Chichester, p 22 Boulton A J M, Gries FA, Jervell J A 1998 Guidelines for the diagnosis and outpatient management of diabetic peripheral neuropathy. Diabetic Medicine 15: 508-514 Budd K 1984 Pain. Update Postgraduate Centre Series. Update, Guildford Cassella J P, Ashford R L, Kavanagh-Sharp V 2000 Effect of applied pressure in the determination of vibration sensitivity using the neurothesiometer. The Foot 10: 27-30
Coppini D V, Weng C, Young P J, Sonksen P H 2000 The 'VPT score' - a useful predictor of neuropathy in diabetic patients. Diabetic Medicine 17: 488-490 Epstein 0, Perkin G, de Bono D, Cookson J 1992 Clinical examination. Gower Medical, London Faris I 1991 The management of the diabetic foot. Churchill Livingstone, Edinburgh Fuller G 1993a Neurological examination made easy. Churchill Livingstone, Edinburgh, p 135 Fuller G 1993b Neurological examination made easy. Churchill Livingstone, Edinburgh, p 135 Fuller G 1993c Neurological examination made easy. Churchill Livingstone, Edinburgh, p 107
NEUROLOGICAL ASSESSMENT
Table 7.20
155
Summary of neurological signs and symptoms
Feature
Site of lesion
Possible disease
Apraxic gait Aphasia, speech defects Visual defects
UMN (hemisphere)
Stroke Hydrocephalus Head injury
Progressive focal deficit epilepsy
UMN (head)
Tumour, ischaemic stroke, previous intracranial disease
Increased tone and reflexes Weak arm extensors Weak leg flexors
UMN (head/spinal cord)
Stroke Cerebral palsy Neck injury Multiple sclerosis
Hypo/bradykinesia Festinating gait Lead-pipe/cog-wheel rigidity Rest tremor
Neck, cervical region
Basal ganglia
Parkinson's disease
Choreo-athetotic movements
Basal ganglia
Huntington's chorea Sydenham's chorea (rare)
Nystagmus Dysarthria Cranial nerve palsies
Brain stem
Multiple sclerosis Syringomyelia
Nystagmus Dysarthria Scanning speech Diminished, pendular reflexes Intention tremor Ataxic gait Dysdiadochokinesia
Friedreich's ataxia Stroke Tumour Vitamin B12 deficiency Syringomyelia Spina bifida
Cerebellum Spinal cord
Diminished tendon reflexes Paresis/paralysis Pain Paraesthesia/anaesthesia
LMN (Spinal cordi nerve roots/axons)
Poliomyelitis Diabetes mellitus Chronic alcoholism Guillain-Barre syndrome Rheumatoid arthritis Charcot-Marie-Tooth disease Vitamin deficiencies (Bl' B6 , B12 ) Tumour Disc protrusion Trauma
Progressive fatiguability and weakness
Neuromuscular junction
Myasthenia gravis
Proximal limb muscle weakness and wasting, but no sensory loss and no fasciculation
Muscle
Myopathies
Fuller G 1993d Neurological examination made easy. Churchill Livingstone, Edinburgh, pp 41-42 Galardi G, Amadio 5, Maderna L et al 1994 Electrophysiologic studies in tarsal tunnel syndrome diagnostic reliability of motor distal latency, mixed nerve and sensory nerve conduction studies. American Journal of Physical Medicine and Rehabilitation 73: 193-198 Ganong W 1991a Reviews of medical physiology, 15th edn. Lange, London, p 200 Ganong W 1991b Reviews of medical physiology, 15th edn. Lange, London, pp 132-133
Golding D N, Rose D M, Selvarajah K 1986 Clinical tests for carpal tunnel syndrome: an evaluation. British Journal of Rheumatology 25: 388-390 International Consensus on the Diabetic Foot 1999 International Working Group on the Diabetic Foot, p 32 Kalter-Leibovici 0, Yosipovitch G, Gabbay U, Yarnitsky D, Karp M 2001 Factor analysis of thermal and vibration thresholds in young patients with Type 1 diabetes mellitus. Diabetic Medicine 18: 213-217 McClintic J R 1980 Basic anatomy and physiology of the human body. John Wiley, New York
156
SYSTEMS EXAMINATION
McGill M, Molyneaux L, Yue D K 1998 Use of the Semmes-Weinstein 5.07/10 gram monofilament: the long and the short of it. Diabetic Medicine 15: 615-617 McLeod J, Lance J 1989a Introductory neurology, 2nd edn. Blackwell Science, Oxford, pp 210-211 McLeod J, Lance J 1989b Introductory neurology, 2nd edn. Blackwell Science, Oxford, p 282 Matthews P, Arnold D 1991 (eds) Diagnostic tests in neurology. Churchill Livingstone, Edinburgh Melzack R 1992 Phantom limbs. Scientific American, April: 90 Nakayama H, Noda K, Hotta H, Ohsawa H, Hosoya Y 1998 Effects of ageing on numbers, size and conduction velocities of myelinated and unmyelinated fibers of the pelvic nerve in rats. Journal of the Autonomic Nervous System 69: 148-155 Root M L, Orien W P, Weed J H 1977 Normal and abnormal function of the foot. Clinical biomechanics - volume 2. Clinical Biomechanics Corporation, Los Angeles, p 254 Vander A J, Sherman J H, Luciano D S 1998 Human physiology, 7th edn. McGraw Hill, New York, pp 238-239 Van Gijn J 1975 The Babinski response: stimulus and effector. Journal of Neurology, Neurosurgery and Psychology 38: 180-186
Van Schie C H M, Abbott C A, Shaw J E, Boulton A J M 1998 A simple method for measuring temperature perception threshold in diabetic neuropathy. Diabetic Medicine 15: S66 Wareham A, Rayman A, Rayman G 1997 Pin-prick sensory thresholds in detecting risk of neuropathic ulceration. Diabetic Medicine 14: S32 Wilkinson I M S 1993a Essential neurology, 2nd edn. Blackwell Science, Oxford, p 135 Wilkinson I M S 1993b Essential neurology, 2nd edn. Blackwell Science, Oxford, pp 49-50 Wilson K J W 1990 Ross & Wilson Anatomy and physiology in health and illness. Churchill Livingstone, Edinburgh Winkler A S, Ejskaer N, Edmonds M, Watkins P J 2000 Dissociated sensory loss in diabetic autonomic neuropathy. Diabetic Medicine 17: 457-462 Young M, Matthews C 1998 Neuropathy screening: can we achieve our ideals? The Diabetic Foot 1: 22-25 Zouri M, Feki M, Hamida C B et al1998 Electrophysiology and nerve biopsy: comparative study in Friedreich's ataxia and Friedreich's ataxia phenotype with vitamin E deficiency. Neuromuscular Disorders 8: 416-425
FURTHER READING Berkow R (ed) 2000 The Merck manual. Merck Sharp & Dohme Research Laboratories, New Jersey Fuller G 1993 Neurological examination made easy. Churchill Livingstone, Edinburgh Joel A, Delisa J B (eds) 1993 Electrodiagnostic evaluation of the peripheral nervous system. In: Rehabilitation
medicine: principles and practice, 2nd edn. Lippincott, Philadelphia Kandel E, [essel T, Schwartz J 1991 The principles of neural science. Elsevier, New York Wilkinson I M S 1998 Essential neurology, 2nd edn. Blackwell Science, Oxford
CHAPTER CONTENTS Introduction 157
Orthopaedic assessment
Terms of reference 157 Position of a part of the body 158 Joint motion 158 Position of a joint 161 Deformity of a part of the body 161
P. Beeson
Why is an orthopaedic assessment indicated? 161 The assessment process 162 General assessment guidelines 163 Gait analysis 167 Abnormal gait patterns
173
Non-weightbearing examination 175 Hip examination 175 Knee examination 181 Tibia/fibularexamination 186 Ankle examination 187 Midtarsaljoint 194 Metatarsal examination 194 Metatarsophalangeal joints (MTPJs) 196 Interphalangeal joints (IPJs) 197 Alignment of the leg and foot 197 Static examination (weightbearing) Limb-lengthinequality 206 Summary 209
202
INTRODUCTION Orthopaedic lower limb assessment is an essential component of the primary patient evaluation. It involves both static and dynamic assessment of musculoskeletal function. Movement of the lower limb involves interaction between the musculoskeletal and the nervous system. This chapter concentrates on the assessment of the musculoskeletal system. Details of the neurological basis of movement and assessment of the nervous system are covered in Chapter 7. The assessment process is based upon an approach which involves general observation of the patient, specific joint observation, palpation, examination of movements and conduction of special tests (McRae 1997). Qualitative, semiquantitative and quantitative measurement techniques are used. The practitioner should be aware of the likely errors that can ensue from such measurements and take these into consideration when interpreting and analysing data from the assessment (see Ch. 4). This chapter concentrates on assessment of the lower limb: details regarding the upper limb and spine have been excluded but can be found in other texts.
TERMS OF REFERENCE The body is divided into three cardinal planes: sagittal, frontal (coronal) and transverse (Fig. 8.1). These planes form the reference points from which to describe: 157
158
SYSTEMS EXAMINATION
I-----=.:~~_t-L=-=-=_~--- Sagittal plane
t - - - - Frontal plane
Transverse plane
Figure 8.1 Cardinal planes of the body: sagittal. frontal and transverse. Sagittal divides the body into right and left halves. frontal divides the body into front and back and transverse divides the body into upper and lower sections. The diagram shows midplanes but the terms refer to any plane parallel to the appropriate midplane.
• • • •
position of a part of the body joint motion position of a joint deformity of a part of the body.
Position of a part of the body The cardinal body planes are used as reference points to describe positions within the body. Anterior (to the front of) and posterior (to the rear of) describe positions in the frontal plane, e.g. the patella lies anterior to the knee joint. Distal (away from the centre) and proximal (towards the centre) describe positions in the transverse plane, e.g. the interphalangeal joints (IPJs) lie distal to the metatarsophalangeal joints (MTPJs). Medial (towards the midline of the body) and lateral (away from the midline of the body) describe positions in the sagittal plane, e.g. the navicular
lies on the medial side of the foot and the cuboid on the lateral side. In the foot, dorsal is used to refer to the top of the foot and plantar to the sole of the foot.
Joint motion Sagittal plane. Motion in the sagittal plane produces extension and flexion. The term flexion denotes the bending of a joint, whereas extension denotes the opposite, i.e. straightening of a joint. The terms used to describe sagittal plane motion in the foot are slightly different from those used to describe such motion at the hip and knee (extension and flexion). At the ankle (Fig. 8.2), subtalar joint (STJ), midtarsal joint (MTJ), metatarsophalangeal joint (MTPJ), interphalangeal joint (IPJ) and first and fifth rays, sagittal plane motion is termed dorsiflexion and planiarilexion. Dorsiflexion denotes a raising of the whole or part of the foot towards the leg, whereas plantarflexion denotes the movement of the dorsal aspect of the foot away from the leg. Frontal (coronal) plane. Motion in the frontal plane produces abduction and adduction of the thigh and leg and inversion and eversion of the foot. This is because the foot lies at right angles to the leg, so the terminology used to describe movements of the foot differ from that for the leg and thigh. Abduction is when the distal segment moves away from the midline of the body and adduction when it moves towards the midline. For example, in order to do the 'splits' gymnasts must abduct their legs. Inversion of the foot is when the plantar aspect of the foot is tilted so as to move towards the midline of the body. Eversion is when the plantar aspect of the foot is tilted so as to face away from the midline of the body (Fig. 8.3). Transverse plane. Motion in the transverse plane produces internal and external rotation of the thigh and leg and adduction and abduction of the foot. Internal rotation occurs when the anterior surface of the distal segment rotates medially in relation to the proximal segment and external rotation when the opposite occurs - the anterior surface of the distal segment moves laterally in relation to the proximal segment (Fig. 8.4). In the
ORTHOPAEDIC ASSESSMENT
B
A
159
C
Figure 8.2 Sagittal plane motion at the ankle A. Dorsiflexion: movement of the foot toward the anterior aspect of the tibia B. Neutral position C. Plantarflexion: movement of the foot away from the tibia.
A
B
Figure 8.3 Frontal plane motion in relation to the midline of the body (black line) away from the line B. Eversion: the foot is moved down and towards the line.
A. Inversion: the foot is lifted up and
160
SYSTEMS EXAMINATION
A
B
c
D
E
Figure 8.4 Relationship between transverse plane motion in the leg and transverse plane motion in the foot A. The feet are mildly abducted; this is the normal standing position B. The legs are externally (laterally) rotated, which results in abduction of the feet (C) D. The legs are internally rotated (medially), which results in the adduction of the feet (E).
ORTHOPAEDIC ASSESSMENT
foot the use of the terms adduction and abduction is dependent upon the site of the reference point: the midline of the body or the midline of the foot. Functionally, the midline of the body is usually used as the reference point: abduction of the foot is where the distal part of the foot moves away from the midline of the body and adduction when the distal part of the foot moves towards the midline of the body (Fig. 8.4). Anatomically the midline of the foot is commonly used as the reference point: e.g. adductor hallucis is inserted into the lateral side of the proximal phalanx of the hallux and is so termed because it brings about adduction of the hallux - movement of the hallux towards the midline of the foot. Triplanar motion. The position of the joint axis together with the shape of the articulating surfaces can result in joint motion in more than one plane. If a joint axis is positioned at an angle of less than 900 to all the cardinal body planes triplanar motion occurs - pronation and supination. Pronation is the collective term for dorsiflexion, eversion and abduction and supination for plantarflexion, inversion and adduction. In the foot the subtalar and midtarsal joints produce triplanar motion.
161
Deformity of a part of the body The term 'deformity' is used to describe a fixed position adopted by a part of the body. Terms used to denote deformity usually have the suffix -us:
• Sagittal plane - equinus when the foot or part of the foot is plantarflexed, e.g. ankle equinus, and extensus when the foot or part of the foot is dorsiflexed, e.g. hallux extensus. Calcaneus, although rarely seen, is used to describe the calcaneus when it is in fixed dorsiflexion, e.g. talipes calcaneovalgus. • Frontal plane - varus and valgus (Fig. 8.5). • Transverse plane - adductus or abductus.
Position of a joint To describe the position of a joint the suffix -ed is used:
• sagittal plane - extended and flexed (thigh and leg); dorsiflexed and plantarflexed (foot)
• transverse plane - internally and externally rotated (thigh and leg); adducted and abducted (foot) • frontal plane - abducted and adducted (thigh and leg); inverted and everted (foot) • triplanar - pronated and supinated (foot). It is important that a distinction is made between joint motion and position; a joint moves in the opposite direction to the position it is in. For example, at heel-strike the foot is slightly supinated (position) but as soon as the heel contacts the ground pronation (motion) occurs at the subtalar joint in order to absorb shock from ground contact.
Genu varum (bow leg)
Genu valgum (knock knees)
A
B
Figure 8.5 Frontal plane deformity of the legs A. Genu valgum (knock knees): the knees are close together and the medial malleoli are far apart B. Genu varum (bow legs): the knees are far apart and the medial malleoli are close together.
162
SYSTEMS EXAMINATION
Table 8.1
Factors that can affect normal function
• Hereditary/congenital problems, e.g. Charcot-Marie-Tooth disease, talipes equinovarus, CDH • Acute/chronic injury causing pain, e.g. slipped femoral epiphysis, ankle sprain • Abnormal alignment secondary to trauma, e.g. femoral/ tibial! epiphyseal fracture • Abnormal alignment (developmental), e.g. internal femoral torsion, genu valgum • Infections, e.g. tuberculosis • Neurological disorders, e.g. CVA • Muscle disorders, e.g. Duchenne's muscular dystrophy • Neoplasia, e.g. osteosarcoma • Systemic disease, e.g. autoimmune (rheumatoid arthritis), bone disease (Paget's disease) • Degenerative processes, e.g. osteoarthritis • Joint hypermobility, e.g. Marfan's syndrome • Osteochondroses, e.g. Perthes' disease • Psychological factors, e.g. attention seeking • Footwear, e.g. high-heeled shoes
WHY IS AN ORTHOPAEDIC ASSESSMENT INDICATED? Normal lower limb function should be pain-free and energy-efficient. The main purpose of the assessment is to identify whether the system is functioning within the boundaries of 'normality'. Normal function can be affected by many factors (Table 8.1). It should be remembered that orthopaedic lower limb problems are not always isolated in origin. They may result from referred pain from a proximal source or can be part of a systemic disorder. It is therefore important that the lower limbs are not examined in isolation and that observation and examination of other parts of the body are undertaken where indicated. In summary the purpose of an orthopaedic lower limb assessment is to: • establish the main complaintts), e.g. pain, stiffness, tenderness, numbness, weakness or crepitus • identify the site of the primary problem - e.g. foot, leg, knee, hip - and try to relate to underlying structures • identify any secondary problems and relate them to the primary problem, e.g. lesion patterns, pronation due to leg-length discrepancy • identify the cause of the problem, e.g. abnormal alignment
• establish how the problem evolved • identify any movement/activity that produces/exacerbates symptoms • identify movement/activity that relieves symptoms • establish any differential diagnoses • utilise the data from the assessment to produce an effective management plan • utilise the data from the assessment to monitor the progress of the condition.
The assessment process When undertaking an assessment of the lower limb it is essential that the system is observed weightbearing (dynamic and static) and nonweightbearing. Differences between the two can help to determine whether compensation has occurred. For example, non-weightbearing assessment may identify the presence of a forefoot varus; observation of the patient's gait may show this problem has been fully compensated through abnormal pronation at the subtalar joint. Conversely, information from the non-weightbearing assessment may explain the cause of a gait abnormality, e.g. a patient may have a bouncy gait due to an early heel lift; non-weightbearing assessment of the ankle joint may reveal that the cause is an ankle equinus due to a short gastrocnemius muscle.
ORTHOPAEDIC ASSESSMENT
To gain a full and detailed picture of the function of the locomotor system, the following factors must be assessed: • • • •
gait alignment and position of the lower limb joint motion muscle action.
Practitioners vary as to the sequence in which they assess the above. There is no one correct sequence; practitioners should adopt the sequence and approach they feel most comfortable with. However, it is essential that a systematic approach is adopted to ensure vital pieces of data are not omitted. For the purposes of this chapter the following sequence has been adopted: 1. Gait analysis. This will focus on the position
and alignment of the body and foot-ground contact. 2. Non-weightbearing. This will focus on the assessment of joints and muscles. 3. Static weightbearing. This will focus on the position and alignment of the body and the relationship of the foot to the ground during stance. To achieve a successful assessment it is important that the patient is at ease and cooperates with and has confidence in the practitioner. The practitioner should always be sensitive to the patient's needs and explain what she is about to do, and why, prior to undertaking the assessment. Qualitative and quantitative measurement should be undertaken where necessary, but the data must be meaningful and reproducible if they are to be of any use in assessing improvement or deterioration. Various measuring devices may be used; their use will be discussed in the appropriate sections.
General assessment guidelines Always observe and functionally assess the joints bilaterally. It is valuable to obtain an overview of both limbs, particularly if the onset of the problem is insidious, the pain is diffuse and nonspecific or if during testing a number of joints appear to be implicated. Where only one limb is affected, it is often helpful to start with the unaffected limb first, then repeat the test on the
163
affected limb. Compare ranges of motion, end feel (the sensation the examiner feels when he pushes the joint being examined to the end of its range of motion) and muscular strength. It is helpful to arrange your testing so that the most painful test is last. This ensures that the condition will not be aggravated by your testing procedure or make the patient apprehensive. Not all of the tests will be necessary for each component of the lower limb assessment. The selection of tests used will depend on the findings as the examination proceeds, and should be influenced by the history and observations in order to rule out needless testing: having said that, it is necessary to be thorough enough to rule out all other possibilities by applying a holistic approach. Exclusion of all possible injured structures in addition to vascular, visceral and systemic conditions will be required. Referred pain associated with local nerve entrapments or radicular patterns of pain in which spinal nerves or nerve roots are irritated need to be considered. In addition, it is important to rule out the joint above and below, especially if the history suggests other joint involvement. Furthermore, it is useful to remember that a problem that affects one part of the system can lead to problems elsewhere in the system. This is because the lower limb functions as one mechanical unit; as a result a problem in one part has to be compensated for in another part of the system. Compensation is a change in structure, position or function of one part in an attempt to adjust to an abnormal structure, position or function in another part. For example, a scoliosis of the spine may lead to an apparent leg-length discrepancy, which will affect foot function. Conversely, a problem affecting the foot, e.g. an uncompensated rearfoot varus, may lead to discomfort/pain at the knee. The process of assessment follows a standard format: • • • • • • •
general observation of the patient specific joint observation palpation examination of joint movement muscle assessment undertaking special tests arranging further investigations.
164
SYSTEMS EXAMINATION
General observation of the patient
The assessment process starts in the waiting room. Observation of the patients' demeanour, facial expression, seated posture and how they get up from the chair will provide valuable clinical information. In addition, the way in which the patient walks into the clinic, together with use of walking aids, provides additional information as to mobility and how this might be influencing lower limb / foot function. Specific joint observation
Observation of each lower limb joint prior to examination is useful to establish the presence of any clinical features synonymous with pathology, e.g. oedema, contusion, erythema, local muscle wasting, alteration in shape or the presence of scars. In addition, comparison of symmetry of contralateral parts, abnormal posture/evidence of limb shortening and abnormal joint movement during gait are additional clinical clues to underlying pathology. Palpation
The process of joint assessment should be based upon the following approach: • • • • •
range of motion (ROM) direction of motion (DaM) quality of motion (QOM) symmetry of motion (SaM) dislocation and subluxation.
Range of motion (ROM) is the amount of motion at a joint and is usually measured in degrees. The ROM at a joint can be compared with the expected ROM for that joint; e.g. if only 20° of motion is found at the first MTPJ when the expected norm is 70° (28% of the normal ROM) it can be concluded that the ability of this joint to carry out normal function is impaired (hallux limitus). Often a guesstimate of the amount of joint motion is made from observation. Protractors, tractographs and goniometers can be used to quantify joint motion (Fig. 8.6). A joint may show a normal ROM but the direction of the motion (DaM) may be abnormal. It is, therefore, important to note the direction as well as the range. For example, the total ROM of transverse plane rotation at the hip is 90°; 45° internal rotation and 45° external rotation. If the ROM is 90° but there is 70° of external rotation and 20° of
Palpation of the limb segment or joint for clinical features such as raised/lowered skin temperature, swelling/effusion, tenderness, pain or abnormal lumps/nodules provides additional information to help establish a diagnosis. Examination of joint movement A
Features of an inflamed joint are redness, heat, pain, swelling and loss of function. Inflammation of a joint may be due to a range of factors: trauma, infection, loose body (osteochondritis diseccans), Examination of the joint, information from the medical and social history and results from X-ray and lab tests will enable a diagnosis to be made. If a patient complains of a painful joint the characteristic features of the pain should be recorded. Prior to examining a joint it is important that the joint is warmed up (moved through its range of motion); this relaxes the ligaments and muscles and also reduces the viscosity of the synovial fluid.
B
.~ ~ c
Figure 8.6 Devices used to measure joints A. Protractor B. Tractograph C. Finger goniometer. D. Gravity goniometer.
ORTHOPAEDIC ASSESSMENT
internal rotation then the ROM would be normal but the DaM would be abnormal. Normal joint motion should occur without crepitus, pain or resistance (quality of motion or QOM). The ROM and DaM of motion of a joint, e.g. hip, should be the same for both limbs (symmetry of motion or SaM). The presence of asymmetry of motion should always be noted. Joint motion can be affected by the ligaments around the joint. It is important as part of joint assessment to identify any dysfunction of the ligaments, e.g. ligament tear or contracture of a ligament. Finally, joints should be assessed as to whether they are subluxated or dislocated. Dislocation occurs where there is no contact between articulating surfaces of the joint and subluxation where there is only partial contact. The range of active and passive movement of each respective lower limb joint should be examined, documented, compared and contrasted with the contralateral side. It is useful to assess whether passive movement of the joint provokes any pain or guarding (sometimes seen in hallux Iimitus). In addition, it is valuable to document the response to resisted testing (strong/weak/painless/painful) and stability of the joint. This will determine the integrity of the articulating surfaces and ligaments. Provoking crepitus on joint movement is an indication of joint damage. Table 8.2 summarises the main joint changes that can be detected during joint assessment. Often it is helpful to be able to differentiate between articular and capsular damage. In a lesser MTPJ this can be achieved by comparing the results of a compression test (compression of the metatarsal head against the proximal phalanx - to test for articular damage) with a distraction test (dorsiflexion/plantarflexion of a distracted proximal phalanx against the joint capsule dorsally/plantarly). Muscle assessment
Muscles bring about motion at joints. To identify the cause of joint dysfunction and/or pain it is important to differentiate between muscle, ligament and joint abnormality. As a number of muscles may affect anyone joint, it is important to
Table 8.2
165
Joint changes
Type of sensation
Indication
Joint stiffness
Inflammatory/degenerative changes
Tightness or tension
Swelling or protective muscle spasm
Popping
Muscle tear or strain
Snapping
Tendon slipping over bony prominence
Clicking
Meniscal tear or patella rubbing femoral condyles
Grating
Osteoarthritis or osteochondritis
Crepitus (tendon)
Inflammation of tendon
Crepitus (joint)
Articular damage or loose body
Tearing
Muscle or ligament tear
Tingling
Neural or circulatory pathology
Warmth
Local inflammation or infection
Numbness or hypersensitivity
Local nerve or nerve root compression
neutralise the effects of other muscles prior to testing the muscle in question. One way in which a muscle can be neutralised is by flexing the joint which the muscle crosses so that tension is removed. Muscles should be tested for: • • • •
strength tone spasm bulk.
Strength. The Medical Research Council (MRC) system is commonly used for grading muscle strength (Crawford Adams & Hamblen 1990):
o = no contraction 1 = a flicker from muscle fasciculi 2 = slight movement with gravitational effects removed 3 = muscle can move part against gravity 4 = muscle can move part against gravity + resistance 5 = normal power. Muscle strength can be assessed by the patient bringing about the motion (active) or by the prac-
166
SYSTEMS EXAMINATION
titioner moving the part (passive). Active motion can be tested against resistance, i.e. the practitioner attempts to prevent active motion. Tone. All muscles should show tone. Tone denotes that a muscle is in a state of partial contraction without full movement being necessary. Asking the patient to undertake isometric contraction of a muscle is a useful means of identifying tonal quality. For example, the tone of the quadriceps can be assessed by asking the patient to contract the muscle while the knee is in an extended position. During contraction muscles should feel firm as well as appearing taut. Flaccid muscles lack tone; this is common with lower motor neurone disorders. Absence of tone in young males could be due to Duchenne's muscular dystrophy. Spasm. Muscles may present in spasm and as a result affect joint motion. There are two types of muscle spasm: tonic and clonic. Tonic spasm usually occurs as an attempt by the muscles to stop movement at a painful joint; clonic spasm is associated with neurological (upper motor neurone) deficit and is involuntary. Information from the neurological assessment, medical history and presenting problem should enable identification of the type of spasm. Bulk. Muscle bulk should be observed and comparisons made between the lower limbs. Atrophy of muscle can result in a loss of muscle bulk and may be due to a number of factors, e.g. lack of use, lower motor neurone lesion (Case comment 8.1). Hypertrophic muscles that show normal tone and symmetrical distribution are considered normal and are usually due to the effects of exercise. Unilateral atrophy/hypertrophy can be assessed by observation and measuring the girth of both limbs with a tape measure (Fig. 8.7).
Case comment 8.1 Be mindful of diabetics who inject themselves with insulin. The quadriceps and abdominal muscles are often used and will show patchy loss of fat and muscle.
ligament. The section on non-weightbearing examination will discuss the specific tests used to assess each of the lower limb joints and their associated structures. Arranging further investigations
Usually the information obtained from a detailed history and assessment is sufficient to arrive at a
Undertaking special tests It may be necessary to carry out specific examina-
tion tests so as to confirm a diagnosis or to differentially diagnose between similar conditions. Some clinical examination techniques have been developed so as to test a particular aspect of joint function, e.g. Lachman's test - to assess sagittal plane stability of the knee in an anterior direction and thereby the integrity of the anterior cruciate
Figure 8.7 Assessment of muscle bulk (quadriceps) using a tape measure.
ORTHOPAEDIC ASSESSMENT
diagnosis. Occasionally, however, it may be necessary to arrange specialist investigations to confirm the diagnosis or to consider other options. A number of possibilities are available, including: specialist imaging techniques and haematological, biochemical and nerve function tests. In addition, histological examination of specimens, electromyography (EMG), video/treadmill gait analysis or computerised analysis/ forceplate analysis may be indicated. The choice of investigation will depend upon the patient's individual history. Furthermore, cost restraints, time, availability of each technique and local expertise will also determine which specialist investigations are arranged.
Table 8.3
167
Dysfunctions that can influence gait
Neurological May involve dysfunction of one or a combination of the following parts of the CNS and/or PNS: • • •
motor, e.g. CVA sensory, e.g. tabes dorsalis, blindness cerebellum, e.g. Friedreich's ataxia basal ganglia, e.g. Parkinson's disease
Systemic • • •
joint disease, e.g. rheumatoid arthritis, osteoarthritis, juvenile idiopathic arthritis crystal arthropathies, e.g. gout muscle disease, e.g. Duchenne's muscular dystrophy, dermatomyositis bone disease, e.g. rickets, Paget's disease
Structural
GAIT ANALYSIS
•
Gait involves complex neuromuscular coordination of the lumbar spine, pelvis, hips and those structures distal to them. Any dysfunction in the lower limb will become observable during gait. A variety of neurological, systemic and structural dysfunctions can influence gait (Inman et a11981) (Table 8.3). The effects of the dysfunctions listed in Table 8.3 may lead to gross or relatively minor changes to gait. Gross disorders are readily observed, whereas those that lead to relatively minor changes, e.g. rearfoot varus, may not be so obvious. Gait can be adequately assessed with few aids, providing that sufficient room is available; ideally there should be a walkway 1.1 m wide and 6 m long. A treadmill may be used; this facilitates the observation of a sufficient number of strides without the patient having to make frequent turns and is especially appropriate if there is not enough room for a 6 m walkway. It is important that the patient is appropriately attired (ideally shorts and 'l-shirt) so that key parts can be observed; these are summarised in Table 8.4. This section concentrates on the observation of gait. Methods of analysing gait are discussed in Chapter 12; these can provide a very useful adjunct to information obtained from observation and are particularly useful in the monitoring of gait changes. The patient's gait must be observed from the posterior, anterior and lateral views in order that movement in all three body
planes can be assessed. Gait should be observed with the patient both barefoot and wearing shoes (with and without orthoses). Gait analysis commences with the patient entering the room. At this point the patient is less conscious of being observed and is less likely to act unnaturally. The practitioner's eye should run from the patient's head to ground level, observing foot-ground contact. At this stage there are some key points the practitioner should address about the patient's gait (Table 8.5). Gait is divided into a swing phase and a stance phase; stance phase relates to the period of the gait cycle when the foot is in contact with the ground and swing phase to when it is not. Stance phase is easier to visualise than swing phase; it consists of the contact, midstance and propulsive stages (Fig. 8.8). Contact phase starts when the heel makes ground contact; this is followed by the rest of the foot. During contact phase the foot pronates in order to absorb shock from the effects of ground reaction. Midstance starts when all the foot is in ground contact and ends with heel lift. During midstance the foot starts to re-supinate ready for propulsion. Propulsion starts at heel lift and ends when the hallux leaves the ground.
limb-length inequality, e.g. DOH, polio, femoral/tibial fracture alignment disorders: coxa valgalvara, genu valgum/varum/recurvatum, tibial/femoral torsion, rearfoot varus
168
SYSTEMS EXAMINATION
Table 8.4 Anatomical and functional features to observe during gait
Head position Shoulder position •
Arm swing
•
Trunk position/rotation Pelvic tilt Limb motion
•
Thigh segment Patellar position (transverse plane) Knee position (frontal/sagittal plane)
•
Tibial position
•
Ankle Calcaneal position Navicular position Midtarsal joint (position/movement) Metatarsals (anterior/lateral views)
•
Toe position Foot position/shape Muscle activity Propulsion Swing phase
During propulsion the foot continues to supinate; the fifth metatarsal head is the first to leave the ground, followed in sequence by the others. The hallux should be the last to leave the ground. Assessment of foot-ground contact and swing phase can be facilitated by high-quality video recording and playback with freeze frame.
Table 8.5
The movement and relationship of both limbs during gait is summarised in Table 8.6. The following section considers each of the specific pointers listed in Table 8.4. Head. The head should not show excessive movement. Altered positions may include twisting (torticollis), due to muscle contracture, or tilting on one side as a result of pain or limb-length inequality (LLI). In type I compensation for LLI the head will tilt down on the long limb side due to cervical scoliosis. In type II and III compensation for LLI the head will tilt down on the short limb side. Shoulder position. Both shoulders should be level. Unilateral tilting may be due to LLI or scoliosis. In children under 12 years with LLI the shoulders will always tilt down on the short limb side (type III compensation). In adults where secondary scoliosis can present the shoulders will tilt down on the long side (type I and type II compensation). Fixed deformities should be distinguished from flexible vertebral deformities (see static weightbearing examination). Arm swing. Arm swing is a feature of normal forward progression. The arms should swing to even out leg movement. The upper torso will act to decelerate lower limb motion. Some subjects fail to swing their arms; this alone is not abnormal but can affect spine position during walking: there is a tendency to lean either forward or back as the arms do not swing. Arm and hand position may point to signs of injury or motor disability and should be recorded: e.g. flexed position of arm and hand held close to the body suggests a cerebral vascular accident (eVA). In addition, in
Questions the practitioner should consider when assessing the patient's gait
Does the patient lurch or look uncoordinated? This suggests ataxia and requires examination of the cerebellum and nervous system. Does the patient have any postural problem? Is the posture abnormal? Does the spine appear curved? Does one leg/foot lead, followed by the other without obvious asymmetry or alteration in cadence? Does the face shows signs of pain or anxiety? Could this be an antalgic gait? Does the patient appear to be overweight in relation to his/her height? Does the whole foot contact the ground when shod? Does the foot look straight, adducted or abducted?
ORTHOPAEDIC ASSESSMENT
Table 8.6
169
Stance phase of gait showing 'normal' movement of the left and right limbs
Left knee/hip
Left foot
Right knee/hip
Right foot
Knee extended Hip flexed
Heel contact
Knee and hip extended
Heellif!
Knee flexed Hip extending
Foot flat (forefoot loading)
Knee and hip flexing to max
Toe-off
Knee extended Hip extended
Midstance
Knee starts to extend from maximum flexion Hip flexed
Midswing
Knee and hip extended
Heel lift
Knee extended Hip flexed
Heel contact
Knee and hip flexing to max
Toe-off
Knee flexed Hip extending
Foot flat (forefoot loading)
A
B
c
D
Figure 8.8 Series of photographs taken at 400 frames per second A. The right heel contacts the ground; forefoot motion is decelerated by the extensor muscles B. The metatarsal heads have contacted the ground but the toes are still dorsiflexed C. The right foot completes forefoot contact and the left heel is about to leave the ground (heel lift) D. Propulsion: the fifth and fourth toes are no longer in ground contact and the third, second and first are about to follow in that order.
170
SYSTEMS EXAMINATION
patients with LU, the arm on the shorter limb side will be held away from the body to help maintain balance and will hang lower than the contralateral arm. Trunk position/rotation. Observe for obvious structural abnormalities likely to influence gait posture such as spinal kyphosis, scoliosis or lordosis. Excessive amounts of trunk rotation will increase energy expenditure during gait and can often be associated with myopathy such as Duchenne's muscular dystrophy and spastic neurological gaits. In addition, excessive upper body movements with the arms swinging across the body may be caused by faulty hip or lower limb mechanics. Pelvic tilt. This forms the pivot of lower limb function. The pelvis moves in all three cardinal planes in order to provide smooth up and down (sinusoidal) motion. Tilting may arise from neurological problems, spinal deformity, LU (pelvis tilts down on side of short limb) and injury. Pelvic tilting can also present in osteoarthritis of the hip due to weakness of gluteus medius (resulting in Trendelenburg gait). Limb motion. Do the limbs present a normal forward progression during gait rather than the exaggerated circumducted movements typical of a CVA patient? Thigh segment. Thigh movement is a reflection of the transfer of pelvic motion through the hip joint. Excessive transverse plane rotation (internal and external rotation) should be noted; this may be due to a variety of factors, e.g. abnormal femoral torsion or version. Patellar position (transverse plane). As long as the patella proves to have normal alignment then it can be used as a reference point to determine the extent of transverse plane motion of the leg. The amount of transverse plane rotation at the knee should be slightly greater than at the hip and may therefore be easier to observe than at the thigh. At heel contact the leg should internally rotate (patellae face inward); throughout midstance and most of propulsion the leg should externally rotate (patellae face outward) (see Fig. 8.4). Alternatively, if the patella has an abnormal alignment, a bisection line drawn through the tibial tubercle with a black felt marker may assist
observation of transverse plane motion. Excessive internal or external rotation should be noted; it may be due to proximal or distal abnormality. If the patellae are squinting with an in-toed gait it suggests the cause of the in-toeing is suprapatellar, whereas if the patellae are facing forward with an in-toed gait the inference is that the cause of the in-toeing is infrapatellar. Excessive externally facing (fish eye) patellae are generally associated with external femoral torsion. Torque conversion is the means by which motion of the thigh and leg influences the foot; the subtalar joint (STJ) is the interface between the leg and foot and is where torque conversion takes place. Internal rotation of the leg is transferred into pronation of the foot (required for shock absorption) and external rotation of the leg is transferred into supination of the foot (required for stability of the foot during propulsion). However, excessive transverse rotations of the leg during gait will influence the angle of gait and, subsequently, promote prolonged and abnormal pronation or supination of the foot, leading to foot and leg pathology. Knee position (frontal/sagittal planes). Sagittal plane motion of the knee joint during gait is outlined in Table 8.6. Alteration in sagittal plane knee motion will affect the third determinant of gait. If the knee does not flex it causes the hip to lift further and allows greater height on that side. To swing the leg from stance through swing back to stance again the pelvis has to rotate more and has a vertical displacement which should appear obvious. Excessive extension of the knee (genu recurvatum) should be noted if it occurs during gait. Frontal plane problems (genu valgus/varum) can be identified from observing the position of the knees and the tibiae. The normal tibial outline shows a slight genu varum because muscle distribution results in lateral bulk. Bowing of the legs (genu varum) or knock knees (genu valgum) should be noted (see Fig. 8.5). Valgum of the hip (coxa) can produce the effect of a genu varum. In addition, osteoarthritis of the medial knee can cause a genu varum deformity. Conversely, coxa vara can produce a genu valgum. If a genu varum or valgum is present, it should be noted if it is bilat-
ORTHOPAEDIC ASSESSMENT
eral or unilateral. A unilateral deformity may suggest injury, infection or growth disturbance at the epiphysis in earlier life. Tumours are a rare cause but should always be considered. Tibial position. Bowing of the tibia in the frontal plane (tibial varus), a cause of rearfoot varus, or sagittal plane bowing (sabre tibia), seen in Paget's disease, should be noted. Ankle. The ankle complex provides smooth transference of weight from heel to toe. A minimum of 10° dorsiflexion is required to allow the leg to pass over the foot during midstance. Equinus is the term used to indicate loss of dorsiflexion. Toe walking and/ or an early heel lift may indicate an ankle equinus but nonweightbearing examination of the ankle joint must be carried out before a definitive diagnosis can be made. Unstable ankles may have frontal plane instability, which shows as tilting hesitations. The subtalar joint works in concert with the ankle (talocrural) joint. Inman (1976) regarded the talocrural (TCJ) and subtalar (STJ) as the 'ankle joint' because they have a symbiotic relationship. The TCJ provides predominantly sagittal plane motion and the STJ frontal and transverse plane motion. If one of these joints is unable to produce motion, e.g. after surgical arthrodesis (joint in fixed position), then the other compensates. Calcaneal position. The posterior position of the calcaneus should be observed. The calcaneus contacts the ground in a slightly inverted position. As a result of ground contact the calcaneus everts, without the need for active muscle contraction, in order to bring the medial tubercle of the calcaneus into ground contact. The position of the calcaneus moves very quickly from an inverted to an everted position; it is therefore often easy to miss subtle changes. At the end of midstance the calcaneus lifts off the ground in order to prepare the foot for propulsion (Case comment 8.2). An early heel lift or a heel that makes no ground contact suggests a neurological problem, an ankle equinus or hamstring tightness. Rapid eversion of the calcaneus at heel contact can be associated with compensation for a rearfoot deformity, e.g. fully compensated rearfoot varus (sometimes described as a heel strike pronator).
171
Navicular position. At heel contact the foot pronates in order to absorb shock from ground contact. During pronation the talar head ad ducts against the navicular and as a result the distance between the ground and the navicular reduces. As the foot progresses into midstance and then toe-off the foot re-supinates (talus abducts); at this point the distance between the navicular and the ground increases. If the talonavicular prominence is visible for more than a moment, or if the extent of the displacement is abnormal, careful examination of the cause must be considered during the non-weightbearing examination. Midtarsal joint (MTJ). During midstance and propulsion the MTJ plays an important role in maintaining foot stability in order to withstand the forces on the foot generated by uneven surfaces and particularly during propulsion. Functioning of the MTJ is difficult to observe during gait. However, if there is abnormal pronation at the subtalar joint the forefoot will appear abducted on the rearfoot at the site of the MTJ; an increased concavity of the lateral border of the foot at the level of the calcaneocuboid joint will be apparent. This is an important sign of dysfunction, which may result in forefoot deformity (Fig. 8.9). Unlocking of the midtarsal joint, known as 'abductory twist', can occur during the last half of midstance should re-supination of the STJ fail to occur. The MTJ unlocks and causes the forefoot to abduct on the rearfoot, resulting in a less springy propulsive phase. The metatarsals. Forefoot loading during the contact phase should be observed from the anterior viewpoint (Fig. 8.8A-C). The fifth metatarsal head makes ground contact first, followed in sequence by the other metatarsals; the first metatarsal head is the last to make ground contact. At propulsion, the reverse should
Case comment 8.2 Given that the average time of contact is between 650 and 750 rns, information has to be rapidly absorbed by the observer. Practitioners may think there is an ankle equinus as a result of gait analysis only to find that on video replay the timing of heel lift is in correct sequence with the opposite foot.
172
SYSTEMS EXAMINATION
Figure 8.9 The foot should be viewed from the posterior aspect to determine subtalar joint and midtarsal joint position during midstance. The midtarsal joint offers a useful gauge to determine deformity due to abnormal pronation, leading to a medial shift in the talonavicular relationship. The lateral border may be very apparent as the foot pronates abnormally. The photograph shows moderate pronation with abduction at the midtarsal joint.
happen; the fifth is the first to leave the ground, followed in sequence by the others, with the first being the last to leave ground contact (Fig. 8.80). During propulsion, motion at the first MTPJ should be observed from the lateral side; ideally, the MTPJ should dorsiflex to approximately 70 0 • Toe position. Toes should be dorsiflexed at contact (Fig. 8.8A,B). Once the first metatarsal has contacted the ground on the medial side, all toes should be plantigrade (Fig. 8.8C). At propulsion the hallux should be the last to leave the ground. Any change in normal digital position
should be noted. The position of the digits during the stance phase is influenced by the intrinsic muscles Oumbricals and interossei) and the long and short flexors and extensors. The role of the intrinsic muscles is to provide transverse plane stability at the distal and proximal IPJs and prevent the toes from buckling under the effects of contraction of the extensors and/or flexors. Clawing of toes during gait can occur if the flexors have a mechanical advantage over the intrinsic and extensor muscles. Conversely, toe clawing can also occur if there is increased extensor muscle activity prior to heel lift.
ORTHOPAEDIC ASSESSMENT
Foot position/shape. When all the foot is in contact with the ground the position of the foot in relation to the midline of the body should be observed. Normally the foot should be slightly abducted (approximately 13°). If the foot is adducted (in-toeing) or excessively abducted (out-toeing) this should be noted together with whether the problem is bi- or unilateral. Foot shape can help inform us about function. Higharched cavoid feet (high STJ axis) produce a greater percentage of internal!external leg rotation, which can result in proximal symptoms in the lower limb. In contrast, low-arched flat feet (low STJ axis) produce increased frontal plane motion, which can result in symptoms in the foot (Green & Carol 1984). Muscle activity. The anterior view allows muscle activity to be observed (Fig. 8.10). Normal 'decelerator' muscle activity can be observed. Deceleration implies that the muscle resists joint movement by eccentric contraction; extensor tendons on the dorsum of the foot are active at contact because they decelerate the foot, prevent foot slap and allow the sole to contact the ground smoothly (Fig. 8.8A,B). Paralysis of the anterior muscle group will lead to a rapid collapse of the foot on to the ground and an audible slap. An example of a severe form of muscle group weakness is shown in Figure 8.11. The peronei, longus and brevis are difficult to identify during gait unless they show spasm. When this happens, and it is not common, the tendons stand out around the lateral malleolus (peroneus longus) and lateral foot (peroneus brevis). Propulsion. A lateral view of the first MTPJ at propulsion is useful to check whether the normal range of dorsiflexion (approximately 70°) is achieved. An alteration in gait at propulsion is often seen in hallux limitus/rigidus to avoid painful dorsiflexion. Furthermore, observation of the whole foot is necessary to assess whether a rigid lever is formed at propulsion and that the foot is not propulsing off an unstable hypermobile forefoot (a cause of first ray pathology). Swing phase. The foot pronates during early swing because the STJ provides additional dorsiflexion with pronation to aid ground clearance. Some neuromuscular conditions may
Muscle belly of extensor digitorum brevis Extensor digitorum .,,------f--c,+t-.c-+I longus
173
Tibialis anterior
Extensor
-::--t-- hallucis longus
Figure 8.10 Muscles on the dorsal aspect of the foot. It is important to observe muscle activity during gait. The contraction of the extensor and tibialis anterior muscles should be clearly seen (Fig. 8.8A,B).
prevent this from occurring and lead to the toes dragging across the ground, e.g. poliomyelitis. Signs of skin lesions over the digits may provide a clue that this is happening. Hip flexors and internal rotators contract to bring the leg forward. If the hamstrings are injured, the time spent in the swing phase will be reduced.
Abnormal gait patterns Gait can be affected in a variety of ways, leading to abnormal gait patterns. Some of the commonly encountered gait patterns are described below. Antalgic gait. This is usually due to a painful muscle, ligament or joint in the lower limb. Furthermore, a painful superficial skin lesion, e.g. verruca, can cause the patient to alter his gait so as to avoid weightbearing on the painful area of the foot. An antalgic gait may commonly be seen following an ankle sprain (lateral ligaments). Apropulsive gait. During the propulsive stage of gait the MTPJs should dorsiflex to approximately 70° and the hallux should be the last digit to leave the ground; if this does not occur, the gait is said to be apropulsive. An apropulsive gait may occur due to a variety of factors, e.g. hallux limitus/rigidus, abnormal pronation, unusual
174
SYSTEMS EXAMINATION
Figure 8.11 The flat-footed and abducted gait has been brought about by muscle paresis (weakness) in the lower leg. Extensive tests have shown no obvious diagnosis. The gait shows shuffle-waddling. There is marked abduction with bilateral ground contact for most of the stance phase. The left foot shows medial roll off as the leg prepares to move into swing.
metatarsal formula, excessive internal rotation of the leg. The foot may compensate for lack of propulsion by rolling off its medial border (Fig. 8.11), by propelling from a hyperextended (dorsiflexion) first IPJ rather than MTPJ or by an abductory twist. This is when the distal part of the foot twists outwards during propulsion. Whatever the cause, the foot is prevented from re-supinating during the later stages of midstance. However, once the heel lifts off the ground the effect of ground reaction, which prevented the re-supination, is reduced and the fore-
foot twists outwards in order to bring the foot into a more medial position for toe-off. Abnormal pronation. Abnormal pronation can be classified as excessive pronation and/or pronation occurring when the foot should be supinating. Signs of abnormal pronation during gait are excessive/prolonged internal rotation of the leg, eversion of the calcaneus, abduction at the midtarsal joint, an apropulsive gait and abnormal phasic activity of the muscles. Early heel lift. This may vary from the heel making no contact with the ground (toe walking)
ORTHOPAEDIC ASSESSMENT
to a relatively normal heel contact but an early heel lift. Heel lift should normally occur at the end of midstance prior to propulsion. An early heel lift can give rise to a bouncy gait. The most common cause is an ankle equinus. Limb-length inequality (LLI). One shoulder is usually lower than the other, and there may be a functional scoliosis. The determinants of gait are affected and the gait appears uneven. The foot of the shorter leg is usually in a supinated position and the foot of the longer leg abnormally pronates. Early heel lift may occur in the shorter leg and prolonged flexion of the knee of the longer leg. Trendelenburg gait. This is characterised by a lurching/waddling gait where the pelvis tilts to the affected side. Associated with congenital dysplasia of the hip and hip osteoarthritis (due to weak gluteus medius), Trendelenburg gait can present following Achilles tendon lengthening procedures and will remain as long as posterior leg muscle weakness persists. Painful knee joint. Avoidance of extension. Painful hip joint. It is commonly held in slight flexion, abduction and external rotation because this puts least stress on the capsule or inflamed synovial membrane. Walking speed and time spent on the involved hip is reduced, e.g. osteoarthritis, Perthes' disease and slipped capital femoral epiphysis. Foot drop or steppage gait. A high knee lift is produced during gait to ensure ground clearance of the affected limb. It is often associated with peroneal damage (Charcot-Marie-Tooth disease), weak tibialis anterior or poliomyelitis. Circumducted gait. A CVA victim has the characteristic features of unilateral limb weakness and will circumduct (rotate the leg in an arc) and flex the elbow and hand towards the body. Movements are made slowly to maintain balance. Jerky movements suggest muscle coordination problems; the nature of upper and lower motor neurone deficits are described in Chapter 7. Scissoring gait. The legs cross the line of progression during gait in cerebral palsy. Circumduction is necessary in order to produce forward motion. Dystrophic/atrophic gait. An exaggerated alternation of lateral trunk movements with an exag-
175
gerated elevation of the hip suggestive of the gait of a duck or penguin is seen in Duchenne's muscular dystrophy (Sutherland et aI1981). Festinating gait. Small accelerating shuffling steps are taken often on tip-toe. This gait pattern is typically associated with Parkinson's disease. Ataxic gait. This condition produces an unstable poorly coordinated wide base of gait pattern. It is primarily seen in patients with cerebellar pathology. Helicopod gait. The feet describe half-circles as they shuffle along during contact and early midstance phase. This condition is seen frequently in hysterical disorder.
NON-WEIGHTBEARING EXAMINATION The prime purpose of the non-weightbearing examination is to undertake an assessment of the joints and muscles of the lower limb. Information from this part of the examination may explain the cause of a gait abnormality or the patient's presenting problem. For example, a foot may in-toe as a result of an osseous and/ or soft tissue problem of the leg; the purpose of the non-weightbearing examination is to establish which is most likely. A flat couch is required for the patient to lie on. The patient should feel comfortable and relaxed and should not wear restrictive clothing. Non-weightbearing examination involves an assessment of the following: • • • • • • • •
hip knee ankle subtalar midtarsal metatarsals metatarsophalangeal joints (MTPJs) digits (proximal and distal interphalangeal joints - IPJs) • alignment of the lower limb.
Hip examination The hip joint is both a mobile and stable joint. Stability is provided by the depth of the acetabulum, strong capsule, capsular ligaments and sur-
176
SYSTEMS EXAMINATION
rounding muscles. Mobility occurs in all three body planes. The primary presenting problem is often hip pain (coxodynia), This is felt deep in the groin, whereas pain on the outside of the femur is often referred pain from the spine. A hip problem can occasionally result in pain being referred (via the obturator nerve) to the knee. A patient who cannot accurately localise pain in the knee should be suspected of having a disorder of the hip. The main cause of hip pain is osteoarthritis, a particularly common condition in the elderly. An X-ray of the hip should be considered if confirmation of a disease process is necessary or diagnosis unclear, e.g. osteoarthrosis, Perthes' disease. It is not usually necessary to examine every patient's hip. The hip should only be examined if the patient complains of discomfort or pain in the area and/or gait analysis reveals an abnormality which affects normal pelvis and thigh/leg motion. Observation of the hip for gross deformity, muscle wasting, oedema, contusion and scar will provide valuable information about potential or past pathology. In addition, palpation of the hip region for joint, muscle pain/tenderness or bursitis (e.g. greater trochanter bursitis due to overuse, weakness of gluteus medius on the opposite side or LLI) is helpful. Where a hip examination is indicated, a series of tests on the hip joint itself in addition to the muscles acting upon it is undertaken.
pelvis while the other hand holds the opposite leg just above the anterior knee and moves the leg towards the body to the point of resistance. Loss of sagittal plane motion may be due to pain, femoral nerve entrapment or effusion in the hip joint as the anterior ligaments (iliofemoral and pubofemoral) will be under greater tension and resistance than usual. Any asymmetry should be noted. Frontal plane. To assess abduction and adduction at the hip the patient lies supine and the practitioner holds the leg just below the anterior knee. The leg with the knee extended is moved across the opposite leg (adduction) and then brought back and abducted. The pelvis should be stabilised during this assessment by placing a hand on the opposite iliac crest. There should be less adduction than abduction at the hip. Tightness of the adductors on abduction can lead to a scissors-type gait: this is when one or both legs have a tendency to cross over during gait and can be seen with cerebral palsy. Transverse plane. Internal and external rotation of the lower limb is essential for normal gait. Ideally, the total range of transverse plane motion in an adult should be 90°, comprising 45° internal and 45° external rotation. Females tend to show more internal rotation than males (Svenningsen et al 1990). The range of transverse plane motion at
Hip joint tests
Assessment of hip motion should be undertaken in each of the three body planes - sagittal, frontal and transverse. Sagittal plane. To ensure forward progression during gait, sagittal plane motion at the hip is necessary. Ideally, there should be approximately 120-140° of flexion and 5-20° of extension, although not all of this is necessary for gait. To assess hip flexion the patient is placed supine on a firm, flat couch. The practitioner holds the leg firmly and flexes the hip by pushing the leg towards the body until resistance is met (Fig. 8.12). To assess extension the patient is placed in the prone position. The practitioner places one hand on the posterior superior iliac crest to stabilise the
Figure 8.12 The patient should be asked to draw the leg towards the stomach as depicted in the photograph. The hip is flexed to its limit against the abdomen. Thomas's test should be considered at the same time by looking for contralateral lifting.
ORTHOPAEDIC ASSESSMENT
the hip decreases with age and the DOM changes from symmetry to more external than internal rotation. To assess transverse plane rotation the patient lies in a supine position. The hip and knees are flexed and the leg is moved medially and laterally as one would the arms of a clock. A gravity goniometer can be used to assess the range of motion (Fig. 8.13). Asymmetry in the DOM should be noted. For example, a patient who shows 70° internal rotation and only 20° external rotation has an internally rotated femur which will affect normal lower limb function and may result in abnormal pronation at the subtalar joint. The test can be repeated with the patient in the same position but with the hip and knees
extended. The practitioner may note a difference in the ROM and DOM at the hip when the knees are flexed compared to when they are extended. It was thought that this technique could be used to detect the presence of torsion (bone influence) or version (soft tissue influence). Torsion was said to exist if there was no difference between the ROM and DOM at the hip with the knees flexed and extended and version if there was a greater ROM when the knees were flexed. It was considered important to make a distinction as torsion cannot be treated conservatively while version can. This concept, while plausible, is not consistent with bone torsion measurement and is open to misdiagnosis. However, it is important when
B
A Figure 8.13
rotation
177
The hips are in a flexed position A. A gravity goniometer is used to assess the amount of internal femoral B. A gravity goniometer is used to assess the amount of external femoral rotation.
178
SYSTEMS EXAMINATION
undertaking an assessment of the muscles around the hip to see if there are any soft tissue contractures, which may be responsible for limiting motion. Contracture of capsular structures of the hip will limit hip movement when these structures are on-stretch (hip extended), whereas contracture of the medial hamstrings will limit external hip rotation with the hip in a flexed position. Scouring/circumduction test. This test is used to assess QOM and joint congruency in patients complaining of groin pain. The hip is flexed and adducted and the practitioner rotates the hip to test for any crepitations. If pain is provoked during this manoeuvre with the hip internally rotated a lesion of the acetabular labrum should be suspected. A posterolateral force applied to the hip will test the integrity of the posterior/lateral hip capsule. Patrick's or faber's test (flexion abduction external rotation). The patient lays supine with one leg
straight. The other knee and hip are flexed so that the heel is placed on the knee of the straight leg. The knee is then slowly lowered into abduction. Gentle pressure is applied to the flexed knee while the opposite hand stabilises the pelvis over the opposite anterior superior iliac spine. This test stresses the medial hip capsule by placing an anteromedial force on the hip, the integrity of the iliofemoral! pubofemoral ligaments and also assesses for sacroiliac discomfort. Sacroiliac joint provocation test. Patients who experience pathology of the sacroiliac joint may complain of pain in the region of the hip. It is therefore important to be able to exclude pathology in the sacroiliac joint. To isolate and test this joint the practitioner places her hands on the anterior superior iliac spines of the pelvis and presses down firmly and evenly to compress the joint and stress the sacroiliac ligaments. The test is positive if the patient experiences unilateral pain in the abdominal-groin, gluteal region or the leg. Hip muscle tests Young's test. A taut tensor fasciae latae causes the knee and hip to flex. By abducting the lower limb, tension on the tensor fasciae latae is reduced
and any flexion deformity should disappear. A tight tensor fasciae latae may be the cause of an apparent limb length discrepancy. Thomas's test. Iliopsoas consists of psoas major, psoas minor and iliacus (the prime flexors of the hip). Thomas's test is used to rule out the presence of iliopsoas contracture. If a flexion deformity exists the affected leg will flex at the knee (see Fig. 8.12) (Case comment 8.3). Furthermore, the femoral nerve can be irritated by a taut iliopsoas group. Damage to the nerve will lead to weakness of the quadriceps, as well as loss of sensation on the anterior and medial aspects of the leg (Case comment 8.4). Ely's test. This test is used to assess hip flexor (rectus femoris) tightness or contracture. The patient lies prone and the knee is slowly flexed as far as possible until the heel comes close to the buttocks. Observe the buttock/hip during this manoeuvre. The point at which the buttock rises off the couch on the tested side indicates the degree of hip flexor tightness. Ober's test. This test is designed to assess for iliotibial band contraction or tightness. The patient lies on his side and the outer limb with the knee extended is moved anteriorly and then adducted towards the couch (Fig. 8.14A). This stretches the lateral structures, primarily the
Case comment 8.3 Thomas's test: while the patient flexes the hip, the practitioner must observe the opposite (contralateral) thigh for any sign of elevation. The lumbar spine must lie flat. If the iliopsoas muscles are tight, the contralateral hip will rise as the ipsilateral hip will force the lumbar spine against the COUCh. Fixed flexion will cause an apparent LLI.
, - - - - - - - - -....._ - - _ . _ - - - - - - - Case comment 8.4 The obturator nerve arises in the psoas major and crosses the hip joint, exiting through the obturator foramen. If this nerve is injured in the hip region, e.g. due to a slipped capita femoris epiphysis, knee pain may result. Where knee pain exists, hip pathology must always be ruled out.
ORTHOPAEDIC ASSESSMENT
Figure 8.14
179
A. Ober's test identifies resistance in the tensor fascia/iliotibial tract B. Assessment of the external rotators. Muscle strength can be gauged by resisting external rotation C. The patient is asked to bring the knees together against resistance. This tests adductor strength.
A
B
C
180
SYSTEMS EXAMINATION
iliotibial band. A modified form of the test separately tests the short fibres of the knee; this is achieved by flexing the knee and repeating the manoeuvre. Piriformis test. With the patient lying on his side, the hip and the knee are flexed to 90°. The examiner places one hand on the pelvis for stabilisation and with the other hand applies pressure at the knee, pushing it towards the couch. This puts the piriformis muscle on tension. If tightness of the piriformis muscle is impinging on the sciatic nerve, pain may be produced in the buttock and also down the leg. Also, in this position the strength of the external rotators of the hip can be tested by asking the patient to externally rotate the hip against resistance (Fig. 8.14B). Adductor strength test. The adductors have their insertion on the medial side of the femur along the linea aspera. The adductor muscles are important during the swing phase, stabilising the contralateral side of the hip against the pelvis as the leg swings forward. Adductor strength can be tested as in Figure 8.14C. Gracilis, a partial adductor, rotates the femur on the hip. As it shares some of the function of the adductors, it can be examined with them. However, this muscle crosses the knee and lies between the sartorius and semitendinosus on the medial aspect of the knee. The knee should be extended to include the action of gracilis, but flexed to remove its influence. Abductor strength test. The abductors include the gluteus medius and minimus as well as tensor fasciae latae. Together they act through the iliotibial tract. Abductor strength is best assessed when the subject lies on his side. The patient should raise the upper leg away from the couch against gravity and resistance. Trendelenburg's test (Stork test). This tests the stability of the hip and the ability of the hip abductors to stabilise the pelvis on the femur. The patient stands on one leg with the other knee flexed; the pelvis should tilt upwards or stay level on the side of the lifted leg. A positive Trendelenburg sign occurs when the reverse happens: the pelvis tilts downwards, indicating weak glutei. Osteoarthritis of the hip can produce a positive Trendelenburg sign.
Laseque's (straight-leg-raise) test. This test will provoke pain in patients with hamstring muscle inflexibility, severe hip pathology and also tests mobility of nerve roots L4 to 52. Where no pathology is present the leg should make an angle of 70° to the supporting surface (Gajdosik et al 1993, Kendall et al 1993). There is no significant difference in hamstring flexibility between males and females (Gajdosik et al 1990).
Functional tests If the patient's pain has not been reproduced
during formal examination, then functional tests should be performed. A single leg squat can be used to assess pelvic control. Abnormalities of excessive lateral or anterior tilt may be noted. Stepup or step-down tests may also be useful.
B
Figure 8.15A,B A. Normal knee anatomy: (1) anterior cruciate (2) posterior cruciate (3) meniscus (4) collateral ligament (5) cartilage (6) ligamentum patellae surrounding patella (7) tibial tubercle B. Diagrammatic representation of the joint margin.
ORTHOPAEDIC ASSESSMENT
Knee examination The knee joint is the largest joint in the body. It is a complex structure which is comprised of the patellofemoral and tibiofemoral joints. The knee should be examined if dysfunction is observed during gait and/ or the patient complains of knee discomfort/pain. To make a comprehensive assessment of knee function a detailed history is required. It is important that the practitioner establishes whether knee pain/discomfort is due to a primary problem affecting the knee, e.g. meniscus tear, or to compensation for a problem
elsewhere, e.g. abnormal pronation causing instability and damage to the knee. Figure 8.15 illustrates the anatomy of the knee joint and the knee joint margin. The knee joint can be compared to a boiled egg lying on a plate; the configuration of an oval femoral surface on a flat tibial plateau allows great mobility. During gait it is important that the knee is stable; the cruciate and collateral ligaments, the menisci and the iliotibial band and sartorius muscles provide most of the stability. The patella forms part of the knee joint; it articulates with the anterior surface of the inferior
C Figure 8.15C
181
Photograph of the joint margin corresponding to B. (Fig. 8.15A,B on facing page.)
182
SYSTEMS EXAMINATION
end of the femur. It acts as a sesamoid as described earlier and provides a key mechanical advantage, increasing the moments of force applied through the ligamentum patellae on to the tibial tubercle. The history should be followed by a comprehensive clinical examination of the knee joint and its associated structures. In view of the number of structures involved, assessment needs to be approached in a systematic manner. The key feature of the knee examination is that each structure that may be injured must be examined. The following scheme of assessment is suggested: • • • • • • • • • •
observation palpation patellofemoral joint tests tibiofemoral joint motion tibiofemoral joint stability integrity of internal knee structure muscle testing Q angle functional tests laboratory tests.
Observation
Prior to formal examination the knee should be observed for: • Gross deformity (genu valgum/varum, enlarged or abnormal position of tibial tubercle). • Patellar position (squinting, fisheye or outward facing, patella alta, patellar tilt or rotation). • Patellar size (small patella unstable in femoral groove, susceptible to subluxation/ dislocation). • Oedema - the presence and site of swelling in the knee should be noted (Case comment 8.5). Swelling of an extreme nature can be associated with bursitis, acute synovitis, tearing of the menisci, rheumatoid arthritis (Baker's cyst) or osteoarthritis. Spontaneous swelling is usually caused by cruciate or meniscus injury or haemarthrosis following trauma. • Tonic muscle spasm (hamstrings) secondary to intra-articular/ extra-articular pain.
Case comment 8.5 A to-year-old male developed a tender area on the anterior aspect of his knee during activity. The site of the tibial tubercle was shown to have been damaged by force from the traction of ligamentum patellae, leaving clinically a hot swollen prominence. The condition was Osgood-Schlatter's disease, a common example of a traction apophysitis. Examination may reveal an old unilateral or bilateral condition typified by an enlarged tubercle.
• Muscle wasting (quadriceps femoris, particularly vastus medialis). Often associated with anterior knee pain, osteoarthritis, rheumatoid arthritis and Osgood-Schlatter's disease. • Bruising (trauma). • Scars (site and size will provide evidence of type/ extent of surgery). Palpation
Systematically palpate the knee to localise areas of pain/ tenderness and thereby isolate the structures involved: • Palpate for warmth (inflammatory joint disorder). • Palpate for oedema (generalised/localised). • Palpate joint line medially /laterally for joint, meniscal pathology and anteriorly for coronary ligament pathology. • Tendons crossing the knee joint: medially (semitendinosus / semimembranosus); laterally (biceps femoris, iliotibial band); and anteriorly (patellar tendon). • Patellar: tenderness superior pole (rectus femoris tear or bipartite patella); pain in body of patellar (fracture following trauma); pain inferior pole of patellar (Sinding-LarsenJohansson syndrome); infrapatellar fat pad palpated for tenderness - this fat pad can become impinged between the patellar and femoral condyle following forced extension of the knee (Hoffa's syndrome); however, chronic fat pad impingement (aka infrapatella bursitis) occurs more frequently.
ORTHOPAEDIC ASSESSMENT
• Popliteal fossa (Baker's cyst, popliteus bursitis, fabella). • Tender, enlarged tibial tubercle (OsgoodSchlatter's disease). • Local oedema. • Bursae (suprapatellar - between quadriceps tendon/femur; prepatellar - between front of patellar/ skin; infrapatellar - between patellar tendon/proximal tibia; pes anserine - under tendinous insertion of gracilis, semitendinosus and sartorius muscles). • Soft tissue lumps such as lipoma can also be found around the knee. Patellofemoral joint tests Ballottement test (patellar tap test). This is used to test for moderate intracapsular swelling. Squeeze excess fluid out of the suprapatellar pouch, place tips of the thumb and three fingers on the patella, and jerk it quickly downwards. A floating sensation of the patella over fluid or a click indicates the presence of an effusion. Wipe test (fluid displacement test). This is used to test for slight to moderate intracapsular swelling. First, evacuate the suprapatellar pouch of fluid; then stroke the medial side of the patellar. A wave of fluid will bulge on the lateral side of the joint. Stroke the lateral side and observe the medial side of the joint for fluid movement. Apprehension test. The patella is manually displaced laterally. If the patient shows signs of apprehension by contracting the quadriceps, this is a positive indication of a subluxing/dislocating patella. 50 :50 test. Displacement of the patella greater than 50% of its width both medially and laterally indicates hypermobility (supported by the Beighton scale). Clarke's test. With the patient supine the practitioner places one hand proximal to the superior pole of the patella and asks the patient to contract the quadriceps. This test is used to detect anterior knee pain, and used to be a popular test for the diagnosis of chondromalacia patellae; however, chondromalacia patella can only really be diagnosed on arthroscopic examination.
183
Tibiofemoral joint motion
The main motion at the knee occurs in the sagittal plane; this is important for forward progression during gait. Ideally, the knee should flex to approximately 135°; the thigh muscles restrict further motion. The amount of sagittal plane motion can be measured with a protractor or tractograph. The amount of extension available is minimal (0-10°). Forced extension of the knee will test the posterior capsule. The knee should extend and lock without pain, with the patella in the centre of the knee. Postural extension beyond 10° is known as genu recurvatum and is indicative of lower limb dysfunction or flexed trunk posture (Riegger-Krugh & Keysor 1996).
Tibiofemoral joint stability Frontal plane. The lateral and medial ligaments of the knee provide stability in the frontal plane. There should be no or limited frontal plane motion at the knee. Frontal plane motion is normally only available to a child under 6 years of age. Lateral collateral ligament stress test (varus stress test). A lateral stress test is used to assess
the lateral collateral ligaments. With the patient supine, the knee is flexed to 30° so the joint is unlocked during the test. The practitioner places one hand on the medial side of the lower end of the femur and the other on the lateral side of the upper end of the tibia. The practitioner then pushes with both hands in an attempt to 'break' the knee by stressing the lateral collateral ligament. Palpation of the lateral collateral ligament (which is deep to biceps femoris) can be made easier using the 'figure-4' position. The patient is seated with the hip maximally externally rotated, the knee flexed to 90° and the foot rested on the top of the distal thigh of the other leg. Medial collateral ligament stress test (valgus stress test). The medial collateral ligament can
then be stressed by placing the hand in the opposite position. Motion at the knee during these tests indicates weak collaterals and poor knee stability. The medial collateral ligament is more commonly damaged (e.g. football/rugby players). The lateral
184
SYSTEMS EXAMINATION
collateral ligament is less commonly damaged (e.g. ice hockey players). Integrity of internal knee structures
Assessment of anterior and posterior cruciate ligaments tests knee stability in the sagittal plane. There are two cruciate ligaments within the knee joint: anterior and posterior. Their purpose is to prevent the knee joint from 'opening up'. Drawer test. To assess the anterior cruciate ligament the patient lies supine with the knee flexed to 45° and the foot flat on the couch. The practitioner sits on the foot and grasps the upper end of the tibia and pulls it forward to stress the anterior cruciate ligament. The posterior cruciate is examined by reversing the manoeuvre. This test is known as the drawer test because the action is like opening and shutting a drawer (Fig. 8.16A). More than 2-3 cm displacement of the tibia is considered abnormal and may be painful; excessive movement suggests tearing of these structures. The Lachman's test specifically tests the anterior cruciate ligaments. The knee is flexed to 25° and the tibia is pulled forward while the knee is externally rotated. If there is displacement of the tibia this is indicative of a weak anterior cruciate ligament. A positive sign is indicated by a forward translation of the tibia with a mushy/soft end feel. The pivot shift test will also assess the anterior cruciate ligaments. With the knee in full extension and the tibia internally rotated, a valgus force is applied to the knee. In an anterior cruciate deficient knee, the condyles will be subluxed. The knee is then flexed, looking for a 'clunk' of reduction, rendering the pivot shift test positive. McMurray's test. This is used to detect meniscus tears. The medial meniscus is most likely to tear because it has less flexibility as it is attached to the capsule. The McMurray test is also designed to seek out any loose bodies by detecting crepitations and clicking (Fig. 8.16B,C). There may be a history of knee locking due to tonic spasm of the hamstrings in order to protect the joint. The patient lies supine with the knee and hip flexed to 90°. The practitioner grasps the sole of the foot with one hand; the other should be placed around the knee so that the joint line can be palpated. By moving
A
B
c Figure 8.16
Knee joint examination A. Drawer test requires the tibia to be push-pulled against the femur B. McMurray's rotation test with the knee flexed and the leg externally rotated C. McMurray's rotation test with the knee flexed and the leg internally rotated.
ORTHOPAEDIC ASSESSMENT
the foot the tibia is externally rotated and a valgus stress is applied. A positive test will elicit a 'popping' or 'snapping' sound or sensation. The test is repeated with internal rotation and a varus stress for the lateral meniscus. Ensure that snapping and clicks due to normal tendon movement over prominences are not misdiagnosed as pathological lesions. Apley's compression test. The patient lies prone and the knee is flexed and the foot grasped. The practitioner creates a compression at the knee joint while producing a rotation movement. A noisy and painful response suggests meniscus damage.
185
action with the quadriceps and a functional equinus at the ankle joint. The 90: 90 test is performed with the patient supine. The knee and hip are flexed to 90°. The practitioner holds the leg and extends the knee until resistance is met. If the knee can be fully straightened or to within 10°, then the hamstrings are within normal limits. If the leg can only be partially extended it indicates tight hamstrings. Any asymmetry should be noted. To assess whether this is due to a tight biceps femoris or semitendinosus, stretch can be placed on the biceps femoris muscle by medially rotating the extended leg and on the semitendinosus by laterally rotating the leg (Fig. 8.18).
Muscle testing Quadriceps. The practitioner should inspect the tone of the quadriceps. Wasting of the medial vastus in particular may occur as a result of knee dysfunction. A tape measure can be used to assess muscle bulk in this area and monitor any change as a result of treatment (see Fig. 8.7). The circumference of both legs should be measured at a standard distance of 10 cm above the superior pole of the patella. The rectus femoris muscle is a weak flexor of the hip but a powerful extensor of the knee. As part of the quadriceps group of muscles, rectus femoris is an important stabiliser of the knee, in conjunction with the vasti, and is needed to swing the leg forward in gait. Pain at its insertion (anterior inferior iliac spine) can arise with a strong kicking action. Examination of the rectus femoris muscle is undertaken with the patient sitting on the edge of the couch with the knees flexed. To assess the strength of this muscle the patient is asked to extend the knee while the practitioner attempts to resist this active motion (Fig. 8.17). Hamstrings. The tone of the hamstrings should be inspected. From an extended knee position the strength of the hamstrings is tested by asking the patient to flex their knee (push down) against resistance. The 90: 90 test is used to identify tightness and contracture of the hamstring muscle group. Tight hamstrings may cause knee flexion, creating an inefficient antagonist
Figure 8.17 Rectus femoris is tested by extending the knee against resistance.
186
SYSTEMS EXAMINATION
Functional tests If the patient's pain has not been reproduced
during formal examination functional tests such as squat,lunge, hop, step-up or step-down should be performed. Laboratory tests
X-rays (anteroposterior and skyline views) may be requested to gain a full picture of the extent of osseous damage to the knee and to rule out osteoarthritis, loose bodies, a fragmented patella or bipartite patella. Ultrasound or magnetic resonance imaging (MRI) will demonstrate thickening/swelling around a tendon, the presence of any tendon tears or degeneration and meniscal damage. Assessment of joint aspirate will rule out haemorrhage, in, e.g. haemophilia, or pus, in, e.g. infective arthritis. Arthroscopy can be combined with surgical exploration of the joint.
Tibia/fibular examination
Figure 8.18 90 : 90 test. The leg can be laterally and medially rotated to identify specific areas of tightness. The photograph shows the leg laterally rotated to identify tight medial hamstrings.
Qangle
The 'Q angle' is the position the patella adopts in relation to the direction of pull of the quadriceps tendon. A line is drawn from the ASIS to a line bisecting the patella. If the angle of this line to the bisection of the patella is greater than 15° the patient is said to have a high Q angle. This suggests medial displacement of the patella and is often associated with greater than normal internal rotation and anterior knee pain.
The tibiofibular segment should be examined for soft tissue swelling. Bilateral swelling suggests a systemic rather than local cause. Unilateral leg oedema in women over 40 years is a common sign of intrapelvic neoplasm. Local swelling is common over inflammatory lesions and stress fractures. Local bone swelling is suggestive of an old fracture or neoplasm (e.g. osteoid osteoma). Multiple or single exostoses occur in the tibia in diaphyseal aclasia. Thickening of the ends of the tibia is seen in osteoarthritis and rickets. The tibiofibular segment should be examined for areas of tenderness. An enlarged and painful tibial tuberosity can be seen in Osgood-Schlatter's disease, tenderness over the proximal/lateral area of the tibia is associated with Brodie's abscess or osteitis, whereas pain in the region of the head of the fibular can be due to proximal tibiofibular joint osteoarthritis. Anterior pain between the tibia and fibular following trauma is seen in anterior tibial compartment syndrome, whereas pain directly over the anterior tibial border is associated with tibial stress fracture. Tenderness in the region of
ORTHOPAEDIC ASSESSMENT
the medial border of the tibia can be associated with medial tibial stress syndrome. Tenderness over the inferior tibiofibular joint may be associated with lateral ligament injury and may cause anterior ankle pain. Tenderness in the back of the calf may be associated with a ruptured plantaris tendon syndrome, whereas pain over the tendo calcaneus may be suggestive of a partial or complete rupture. With the patient prone, Thomson's test can be performed. The calf is squeezed. If no ankle plantarflexion occurs, a complete rupture is indicated. The frontal plane alignment of the tibia should be determined because tibial deformity can influence foot function. This is best performed in the supine position by bringing the legs together and observing the relative distance between the knees and malleoli. A greater distance between the knees is seen in tibial varum. Tibial varum is generally more common than tibial valgum. In the largest normative study, Astrom & Arvidson (1995) reported a mean of 6° of tibial va rum; therefore, a slight tibial varum is considered normal. An excessive tibial varum, however, can lead to a range of lower limb conditions with the development of pathology theoretically dependent on the STJ's ability to compensate. Unilateral overuse injuries are more likely to exhibit larger tibial varum on the affected side (Tomaro 1995). The eight-finger test can also be used to estimate the degree of frontal plane bowing of the tibia. All eight fingers are placed along the anterior border of the tibia and their alignment compared. Sagittal plane bowing (sabre tibia) and general tibial thickening as seen in Paget's disease should not be overlooked (Fig. 8.19). It is also important to assess for any transverse plane deformity of the tibia, as this can influence foot function. Medial tibial torsion is associated with flat feet and intoeing deformities (Thackery & Beeson 1996), whereas a lateral torsional deformity of the tibia is seen in pes cavus. With the patient supine and knees flexed and the soles of the feet on the couch, the relative lengths of the tibiae should be assessed by comparing the heights of the knees (Skyline/Allis test) or tibial tuberosities.
187
Figure 8.19 Patient with severe bowing associated with Paget's disease, 'sabre tibia' affecting patients in the sixth/seventh decade of life. Deformity occurs in the sagittal as well as the frontal plane.
Ankle examination Inman (1976) regards the ankle as a two-joint system comprising the talocrural joint (TCD and the subtalar joint (STD. Motion of the foot is primarily controlled through this joint complex, but the whole proximal segment also relies upon the TCJ and STJ working in concert. Elftman (1960) considered the midtarsal joint to be the third member of the ankle complex. In addition, Brukner & Kahn (1993) consider the inferior tibiofibular joint to be part of the ankle joint complex. The inferior tibiofibular joint is a syndesmosis supported by the inferior tibiofibular ligament. A small amount of rotation is present at this joint. Each of these joints will be considered separately for examination purposes but functionally they should be considered together. Coalitions between the joints making up the ankle complex may be present. The two most common involve the talocalcaneal (medial and posterior facets) and the calcaneonavicular (Kulik & Clanton 1996). Other types may occur but are quite rare. The coalition may be fibrous, cartilaginous or osseous. Fibrous coalitions permit some motion whereas cartilaginous and osseous coalitions produce little motion but more symptoms. Tonic spasm of the peronei is a common finding with tarsal coalitions. X-rays are necessary to diagnose a synostosis (osseous coalition).
188
SYSTEMS EXAMINATION
Talocrural joint The trochlear surface of the talus articulates with the inferior surface of the tibia to form the talocrural joint. The medial and lateral malleoli provide additional articulations and stability to the ankle joint. The talocrural joint is a triplanar joint but, because of the position of its axis and the shape of the joint surfaces, its main motion is in the sagittal plane. The lateral curvature and radius of the trochlear surface of the talus has been found to be variable - the longer its radius, the less dorsiflexion (Barnett & Napier 1952). During midstance there should be at least 100 of dorsiflexion at the ankle in order to allow the leg to move over the foot. The body compensates for a lack of ankle dorsiflexion at the knee and/or subtalar and midtarsal joints. The STJ has less available sagittal plane motion than the TCL but if necessary the STJ will increase the amount available if there is insufficient motion at the TCJ. In addition, the knee can hyperextend (genu recurvatum) as a way of compensating for an ankle equinus. Assessment of TCJ range of motion, stability, strength, palpation for tenderness, grading of ligamentous injury and proprioception are important parts of the ankle joint assessment. Joint motion. The passive range of TCJ plantarflexion and dorsiflexion should be assessed and compared for each limb. Ankle equinus is traditionally defined as less than 100 of dorsiflexion at the TCJ, although some practitioners suggest that less than 50 dorsiflexion leads to abnormal compensation. It may arise from soft tissue or bone abnormalities of an acquired or congenital nature. Assessing sagittal plane motion at the TCJ is difficult. It can be assessed either weightbearing or non-weightbearing. If assessed non-weightbearing the patient should lie in a prone or supine position with the knee extended and the foot and ankle free of the end of the couch. The practitioner holds the foot in a neutral position with one hand, places the other hand on the sole of the foot and dorsiflexes the ankle (Fig. 8.20A). If subtalar joint pronation is allowed to occur during the examination a falsely elevated
dorsiflexion value will result (Rome 1996a, Tiberio et aI1989). The force applied by the practitioner to produce TCJ dorsiflexion can vary; this will have an effect on the result. A tractograph can be used to assess the range of motion but the practitioner may find it difficult to use, while at the same time keeping the foot in a neutral position (Fig. 8.20B). In addition the intra- and interobserver reliability of non-weightbearing TCJ dorsiflexion measurements using a tractograph is questionable (Rome 1996b). A tight soleus and/or gastrocnemius may prevent TCJ dorsiflexion. To differentiate between the two the amount of dorsiflexion with the knee extended and flexed should be measured. With the knee flexed the tendons of gastrocnemius which cross the knee are released from tension and as a result a tight gastrocnemius should not affect TCJ dorsiflexion. If the amount of dorsiflexion is still reduced when the knee is flexed the cause is likely to be soleus (Fig. 8.20C). A bony block (osteophytes on distal! anterior tibia) can also limit "rCJ dorsiflexion with the knee flexed; however, the tendo Achilles in this case will feel slack. Assessment of the TCJ end-of-ROM is useful. Soft tissue limitation will result in a springy endfeel, whereas limitation resulting from a bony block will be abrupt. More consistent results have been achieved when sagittal plane motion is assessed with the patient weightbearing. The patient stands facing a wall with a distance of approximately 0.5 m between the patient and the wall. One leg, with the knee in a flexed position, is placed in front, approximately 30 cm from the wall. The other leg is placed behind the forward foot with the knee extended and the foot held in a neutral position. The patient leans towards and places both hands on the wall and is asked to move his body towards the wall. In order to do this the patient must dorsiflex the ankle of the limb furthest from the wall. The amount of dorsiflexion can be measured with a tractograph (Fig. 8.200). Stability. By moving the TCJ in all three planes the ligaments can be stressed and any tenderness noted. There should be little or no
ORTHOPAEDIC ASSESSMENT
A
C
B
D
189
Figure 8.20 Ankle joint dorsiflexion A. Non-weightbearing assessment of ankle joint dorsiflexion with the knee extended and the foot in the neutral position. Restriction of motion may be due to tight gastrocnemius, soleus or bony block B. A tractograph is used to measure the amount of dorsiflexion C. Non-weightbearing assessment of ankle joint dorsiflexion with the knee flexed and the foot in a neutral position. Restriction with the knee flexed due to a bony block or tight soleus D. Assessment of ankle joint dorsiflexion weightbearing.
displacement in the frontal plane and the patient should find the movement pain-free. Tenderness from the lateral ligaments (calcaneofibular and talofibular) should be noted before stressing the joint at the extreme ends of inversion and eversion. The anterior joint line should be pressed upon firmly at the tibial plafond. The talus may have less stability if the inferior transverse tibiofibular ligament is affected as this holds the distal end of the tibia and fibular within the ankle mortise.
Stability in the sagittal plane can be tested by applying a forward and then a backward push on the TCJ while the knee is flexed and the foot is in contact with the examining couch. This is the drawer test and should reveal minimal positional change and no discomfort. This test assesses the integrity of the anterior talofibular ligament. The talar tilt test will assess the integrity of the calcaneofibular ligament laterally and the deltoid ligament medially. With the patient supine the calcaneus is grasped and moved medially and
190
SYSTEMS EXAMINATION
laterally. The medial and lateral movement of the talus and calcaneus is assessed in relation to the tibia and fibular. Stress X-rays using a German system known as TELOS allows the ankles to be compared (Fig. 8.21). Anterior-posterior shift and lateral stress views can be taken. The procedure is performed under local anaesthesia using a common peroneal nerve block; it provides a reproducible method to determine ankle stability. Functional tests. These tests can be a valuable aid to diagnosis. The lunge test (patient lunges forward while standing) assesses weightbearing ankle dorsiflexion and helps in the diagnosis of anterior impingement syndromes. The singlelimb heel-raise test may be used to aid the diagnosis of tibialis posterior dysfunction syndrome (TPDS). If the manoeuvre induces pain in the region of the tubercle of the navicular extending to the posterosuperior border of the medial malleolus and along the posteromedial tibial border with the calcaneus failing to invert a partial or complete tear of the tendon is indicated. The patient with TPDS will also present with a severely pronated foot. Functional tests such as single-leg standing and hopping can be used to reproduce a patient's pain in other causes of ankle pain. The posterior aspect of the talus should be palpated while the ankle is in a plantarflexed position. Stieda's process may become irritated, or fracture if extra-long, or may appear as a separate bone (os trigonum) and become transiently irritated. The pain is deeper than with soft tissue problems such as a tender Achilles tendon. Strength. Both active movements of ankle plantarflexion/ dorsiflexion, inversion/ eversion and resisted movements of eversion should be assessed using the Medical Research Council system. Grading of ligamentous injury. The lateral ankle ligaments are more commonly damaged than the medial (deltoid) ligament. In the typical inversion and plantarflexion injury, the three parts of the lateral ligament are usually damaged in order, depending on the severity of the sprain: the anterior talofibular ligament (ATFL) followed
Figure 8.21 TELOS: lateral ankle stress test under local anaesthesia (reproduced by courtesy of Fifth Avenue Hospital, Seattle).
by calcaneofibular (CFL) and, finally, the posterior talofibular ligament (PTFL). Complete tear of all three ligaments is usually associated with an ankle fracture. Lateral ligament injuries are divided into three grades: • grade I = minor ATFL tear with pain but no laxity • grade II = painful if stressing ligament with laxity but firm end-point • grade III = gross laxity without discernible end-point. To isolate the specific structure(s) damaged following an ankle injury a number of areas around the ankle should be palpated for tenderness (Table 8.7).
ORTHOPAEDIC ASSESSMENT
Proprioception. Single-leg standing with eyes closed may demonstrate impaired proprioception compared with the uninjured side. Investigations. X-rays (anteroposterior mortice, lateral and oblique views) should be performed after ankle sprains in cases where instability is present or acute bony tenderness is present on the malleoli or the medial or lateral dome of the talus. Ankle X-rays must include the base of the fifth metatarsal to exclude associated fracture. In special cases computed tomography (CT) or MRI scans may be indicated.
Table 8.7
191
Subta/ar joint
The inferior surface of the talus articulates with the superior surface of the calcaneus at three facets. The largest facet forms the posterior joint, which is separated from the others by the interosseous talocalcaneal ligament, which lies in the sinus tarsi. Pain may arise from damage to the sinus tarsi. The STJ produces triplanar motion. Because of the position of its axis - 42° from the transverse plane, 45° from the frontal plane and 16° from the sagittal plane (Root et al 1966) - little movement is produced in the sagittal plane but motion does occur in the frontal and transverse plane (L: 3 : 3).
Structures to palpate following an ankle injury
Tender structure
Possible diagnosis/injury
Distal fibular
Fracture
Lateral malleolus
Fracture
Lateral ligaments
Anterior talofibular ligament/calcaneofibular ligament (ATFUCFL) sprain due to forced inversion/plantarflexion. Complete tear of ATFL, CFL and posterior talofibular ligament (PTFL) follows an ankle fracture
Lateral aspect of talus
Fracture to lateral process of talus
Posterior aspect of talus
Fracture to posterior process of talus or os trigonum fracture
Peroneal tendon
Peroneal tendonitis due to excessive eversion, peroneal dislocation due to forced passive dorsiflexion and tearing of peroneal retinaculum or peroneal rupture
Base of fifth metatarsal
Avulsion fracture due to inversion injury
Anterior joint line
Articular damage (osteoarthritis)
Dome of talus
Osteochondral fracture associated with compressive component of inversion injury (landing from a jump)
Tibialis anterior
Tibialis anterior tendinitis due to overuse of ankle dorsiflexors secondary to restriction in joint range of motion
Posterior medial malleolus
Entrapment of posterior tibial nerve (tarsal tunnel syndrome) due to inversion injury or excessive pronation
Medial malleolus
Stress fracture
Medial (deltoid) ligament
Ligament sprain associated with fractured medial malleolus, talar dome
Tibialis posterior tendon
Tibialis posterior tendinitis (pain is exacerbated by passive eversion)
Sustentaculum tali
Flexor hallucis longus tendinitis (pain aggravated by resisted flexion of hallux or full dorsiflexion of hallux)
Sinus tarsi
Excessive subtalar joint pronation or ankle sprain
Anterior inferior talofibular ligament
The anterior inferior talofibular ligament (AITFL) is damaged in more severe ankle injuries. Occasionally associated with malleolar fractures
192
SYSTEMS EXAMINATION
Alteration of the axis can favour motion in one direction at the expense of motion in another. The knee and foot are affected by the axial position of the STJ (Green & Carol 1984). Joint motion. To measure triplanar motion at this joint one would have to measure the motion produced in each plane; this is impossible to achieve clinically. The amount of frontal plane motion at the STJ can be measured, and this is used as an indicator of the ROM at the STJ. It is important that there is an adequate ROM and appropriate DaM at the STJ for normal pronation and supination of the foot. To assess frontal plane STJ motion the patient lies prone with the ankle and foot hanging over the edge of the couch. The distal third of the leg is bisected; this line is used as a reference point for measuring the ROM and DaM. The calcaneus is moved into its maximally inverted position and the posterior surface of the calcaneus is bisected (Fig. 8.22A). A tractograph is used to measure the angle between the bisection of the leg and the bisection of the posterior surface of the calcaneus. The calcaneus is placed in its maximum everted position and a reading is taken of the angle between the bisection of the leg and the bisection of the posterior surface of the calcaneus (Fig. 8.22B). Although this technique is helpful for clinical assessment, it is not considered accurate (Elveru et aI1988). Milgrom et al (1985) examined 272 male infantry recruits and an error in excess of 20% was identified. It is also recognised that for research purposes its reliability and validity are poor (Menz 1995). Some consider it to be so poor as to suggest that this method of examination no longer be used to determine the measurement of STJ movement (Buckley & Hunt 1997). A weightbearing assessment of STJ ROM would theoretically be a better indicator of the range utilised during walking. There is normally twice as much inversion as eversion (2: 1 ratio). Many patients appear to have a 3 : 1 ratio of inversion to eversion without any abnormal sequelae arising. Subtalar varus
Subtalar varus implies that the neutral position of the calcaneus is varus (inverted) in relation to
the leg bisection (non-weightbearing). Subtalar varus or rearfoot varus (discussed under static examination) can affect the function of the rearfoot during gait and may lead to excessive pronation of the foot and delay re-supination of the foot during gait. Abnormal pronation
Abnormal pronation, i.e. excessive STJ pronation during contact phase and/ or STJ pronation occurring when the STJ should be supinating during midstance and propulsion, is one of the most common disorders of the lower limb. A large degree of frontal plane motion in the foot (due to uncontrolled STJ pronation) is thought to predispose to forefoot pathology and ankle dysfunction, whreas a greater degree of transverse plane tibial rotation is thought to predispose to leg and knee pathology. The presence of four or more of the following indicates abnormal pronation: • more than 6° between the relaxed calcaneal stance position (RCSP) and the neutral calcaneal stance position (NCSP) • medial bulging of the talar head or 'midtarsal break' - quantified using the navicular drift technique (Menz 1998) • lowering of medial longitudinal arch quantified using the navicular drop technique (Mueller et a11993) • more than 4° eversion of the calcaneus • Helbing's sign (medial bowing of the tendo Achilles) • abduction of the forefoot at the MTJ (concavity of lateral border of foot) • apropulsive gait. Numerous conditions arising in the lower limb may lead to abnormal pronation; many of them have been highlighted in this chapter (the list is not exhaustive): • • • • •
internal or external torsion of the leg/ thigh tibial (genu) valgum/ varum coxa vara/ valga ankle equinus rearfoot varus
ORTHOPAEDIC ASSESSMENT
A
193
B
Figure 8.22 Assessing frontal plane motion at the ST J A. The distal third of the leg is bisected and a line is drawn at the bisection point. The posterior surface of the calcaneus is moved into its maximally everted position and the angle between the bisection of the leg and the bisection of the calcaneus is measured B. The calcaneus is moved into its maximally inverted position and the angle between the bisection of the leg and the bisection of the calcaneus is measured.
• inverted forefoot • everted forefoot. For treatment to be effective it is important that the cause and the extent of the abnormal pronation are correctly identified; otherwise, only symptomatic treatment on a trial and error basis can be provided. Examination of muscles affecting the ankle complex Plantarflexors. The posterior group of muscles plantarflex the foot at the ankle but may also restrict the amount of dorsiflexion at the ankle.
The patient should be asked to plantarflex the foot with and without resistance in order to test muscle strength. Rupture or partial rupture of the tendo Achilles should be ruled out. If the tendo Achilles is functioning normally the foot should plantarflex when the calf muscle is squeezed. Plantaris is a small muscle that is not present in everyone. Spontaneous rupture of plantaris may occur; it shows as a painful medial swelling over the posterior aspect of the calcaneus at its insertion near the tendo Achilles. Invertors. Tibialis posterior and anterior are the main invertors of the foot. These extrinsic muscles play an important role in re-supinating
194
SYSTEMS EXAMINATION
the foot during midstance and propulsion. To assess the strength of these muscles the patient should be asked to move his foot into supination against resistance. Dorsiflexors. The main dorsiflexors of the foot are the long extensors and tibialis anterior. To assess the strength of the anterior muscles the patient should be asked to dorsiflex the ankle with the foot in inversion against resistance. Weakness of the anterior group is often linked to neurological problems, e.g. poliomyelitis. The plantarflexors have a work capacity 4.5 times that of the dorsiflexors. If the dorsiflexors are weak the foot is held in a plantarflexed position as the plantarflexors have a mechanical advantage. Evertors. The evertors of the foot are the peronei. To assess the strength of the peronei the patient should be asked to evert the foot against resistance. The evertors are not as powerful as the invertors and in the case of neurological problems and/ or muscle imbalance the invertors have a mechanical advantage over the evertors and the foot is held in an inverted position (following a CVA). Tonic spasm of the peroneal muscles can occur; this is noted particularly with tarsal coalitions. A local anaesthetic can be administered in order to differentiate between a muscle spasm and a tarsal coalition.
Midtarsal joint The MTJ comprises two synovial joint complexes: talonavicular and calcaneocuboid. The MTJ is also known as the transtarsal or Chopart's joint, and is an articulation between the rearfoot and forefoot. The MTJ has two axes: longitudinal and oblique. The longitudinal axis provides frontal plane motion facilitated by the ball and socket joint of the talonavicular articulation. The oblique axis involves both calcaneocuboid and calcaneotalonavicular joints and primarily produces transverse and sagittal plane motion. Limitations of motion at the ankle joint are compensated at the oblique axis of the MTJ. The MTJ assists in reducing impact forces and helps to prepare the foot for propulsion. It can also accommodate walking on uneven terrain
without affecting the rearfoot. This means that the forefoot might invert while the heel remains vertical; the converse does not occur. Joint motion. To assess the motion at the MTJ the practitioner must stabilise the STJ and prevent any motion occurring at this joint by firmly holding the heel with one hand and holding the foot just distal to the midtarsal joint with the other. The MTJ should then be moved in the sagittal, transverse and frontal planes. There should be most motion in the sagittal and transverse planes and minimal motion in the frontal. The position of the axes will affect the amount of motion at the MTJ: e.g. a high (vertical) oblique axis will result in an increase in transverse plane motion but a reduction in sagittal plane motion.
Metatarsal examination The first and fifth metatarsals have independent axes of motion and produce triplanar motion. The second metatarsal is firmly anchored to the intermediate cuneiform and has least motion; the third has less motion than the fourth metatarsal. Whereas the first and fifth metatarsals provide triplanar motion, the central three only move in the sagittal plane. The ability of the first metatarsal to plantarflex is important in order that the medial side of the foot makes ground contact during gait and the first MTPJ can dorsiflex during propulsion. Patients commonly present with cutaneous changes associated with dysfunction of the metatarsals, especially the first and fifth. Sometimes one of the metatarsals may be held in a plantarflexed position. The position of the metatarsals can subsequently affect foot mechanics and gait. Joint motion. Clinical assessment of first and fifth metatarsal motion can only be satisfactorily undertaken in the sagittal plane. Unlike most joints, motion at the first and fifth rays is measured in millimetres, not degrees. To assess sagittal plane motion the patient can be in a supine or prone position. The feet must be allowed to hang free of the couch. The practitioner places one hand, with the thumb to the plantar surface, around the lateral side of the forefoot including the second metatarsal while maintaining the foot
ORTHOPAEDIC ASSESSMENT
195
in its neutral position. The other hand, again with the thumb to the plantar surface, is placed around the first metatarsal. The first metatarsal is moved into maximum dorsiflexion and plantarflexion. It is usual to find approximately 10 mm in each direction (Fig. 8.23A,B). Lack of plantarflexion of the first ray is known as metatarsus primus elevatus. The amount of
motion can be assessed using the thumb technique (Kelso et al 1982) (Fig. 8.23A,B). A Sagittal Raynger provides an alternative means of assessing first metatarsal motion (Fig. 8.23C,D) (Kilmartin et al 1991). Sagittal plane motion of the fifth metatarsal can be undertaken using the same approach. The validity of this technique is questionable, however, as it may not represent
A
B
C
D
Figure 8.23 Assessment of motion at the first ray A. Measurement of dorsiflexion of the first ray using the thumb test B. Measurement of plantarflexion of the first ray using the thumb test C. Dorsiflexion of the first ray measured with a Sagittal Raynger (reproduced by courtesy of Nova Instruments) D. Plantarflexion of the first ray measured with a Sagittal Raynger (reproduced by courtesy of Nova Instruments).
196
SYSTEMS EXAMINATION
the range the first or fifth metatarsal moves through during gait. Deformity. Deformity of the metatarsals is said to occur when the ROM or DOM of one or more metatarsals is asymmetrical or the metatarsal heads do not lie in the same plane. Table 8.8 refers to the various positions and terms associated with the deformities affecting the rays; these may be congenital or acquired. It is not unusual for a problem affecting the metatarsals to be unilateral. Metatarsal parabola. The metatarsal parabola should also be assessed and documented using the palpation technique (Spooner et al 1994), as abnormal metatarsal length is known to be associated with pathology. A short first metatarsal can be associated with the development of hallux valgus, whereas a long first metatarsal can cause hallux rigidus. Shortening of a lesser metatarsal (e.g. brachymetatarsia) can result in the development of intractable plantar keratosis, metatarsalgia or hammer toe deformity. Table 8.8 Abnormal positions ofthe metatarsals Position Normal position
Description
Thefirst and fifth metatarsals exhibit equal motion above and below the second/fourth metatarsal of 10-20 mm (5-10 mm in each direction) Metatarsus primus Reduces ability offirst metatarsal elevatus to bear weight and overloads central (dorsiflexed first metatarsal) metatarsals. Differential diagnosis forefoot varus. Shows limited plantarflexion and cannot be reduced below level ofsecond metatarsal Flexible plantarflexed Thefirst metatarsal may appear first metatarsal pronounced on the plantar surface ofthe foot with a cleft between the first and second metatarsal heads. Most ofthe movement is in the plantar direction. Loading the metatarsal head produces reduction ofthe position Rigid plantarflexed Thefirst metatarsal cannot be first metatarsal reduced at all from its plantarflexed position. Theforefoot tends to rotate in inversion during weightbearing; this affects rearfoot function
Metatarsophalangeal joints (MTPJs) The MTPJs are the joints between the metatarsals and the proximal phalanges; they produce motion in the sagittal plane. During the propulsive period of gait it is important that dorsiflexion occurs at these joints in order to facilitate toe-off. Joint examination. The ROM and DOM in the sagittal plane should be assessed for all MTPJs; they should have a free range of motion without pain or restriction (Fig. 8.24). The first MTPJ has the greatest range of motion: approximately 70-90° dorsiflexion and 20° plantarflexion (Bojson-Moller 1979). The ROM and DOM at the first MTPJ can be assessed with a tractograph or finger goniometer. The practitioner should appreciate that the declined angle of the first ray accounts for at least 15° of dorsiflexion at rest. A lack of dorsiflexion at the first MTPJ is known as hallux limitus, and a complete absence as hallux rigidus. The presence of either of these conditions, but particularly hallux rigidus, will affect toe-off and can lead to an apropulsive gait and overloading of one or more of the other metatarsal heads. Some authors also consider that this interferes with the angular momentum of the body (Miyazaki & Yamamoto 1993) and predisposes to the development of chronic postural complaints (Dananberg 1986, 1993). Hallux flexus is not so common; this is where the proximal phalanx adopts a plantarflexed position. Hallux extensus (trigger toe) is where the proximal phalanx is abnormally dorsiflexed; it is often associated with pes cavus. Restriction of movement at MTPJs could be due to osteophytes, loose bodies or articular damage, e.g. osteochondritis dissecans. The effects of Freiberg's disease may be to produce an enlargement of the metatarsal head and early osteoarthritic changes; this usually affects the second or third metatarsal. In some patients, particularly younger ones, the clinical appearance of the joint may appear normal and X-rays may reveal no abnormalities. It is essential in these cases that spasm of flexor hallucis brevis and/ or abductor hallucis is ruled out via the use of local anaesthetic blocks.
ORTHOPAEDIC ASSESSMENT
A
B
C
D
197
Figure 8.24 Assessment of motion at the MTPJs A. Dorsiflexion of the first MTPJ B. Plantarflexion of the first MTPJ C. Dorsiflexion of the second MTPJ D. Plantarflexion of the second MTPJ. In both cases (first and second MTPJ) dorsiflexion is greater due to the shape of the articular surfaces.
Interphalangeal joints (IPJs)
Alignment of the leg and foot
Toes have considerably less functional movement than fingers. The practitioner should note any restriction or fixed deformity affecting either the proximal (PIPJs) or distal (DIPJs) joints. Joint examination. The PIPJs can plantarflex (approximately 35°) but cannot dorsiflex (Fig. 8.25A). The DIPJs can dorsiflex to 30° and plantarflex up to 60° (Fig. 8.25B,C). The patient may be unable to actively move the toes to assess the function of the intrinsic muscles. However, plantarflexion can be assessed by placing the fingers under the apices of the toes and asking the patient to claw the toes around them.
While the patient is lying on the couch the following should be assessed: • • • • • • •
presence of genu varum/valgum malleolar torsion rearfoot to forefoot alignment arch height metatarsal formula toe position foot length.
Genu varumlvalgum. To assess the presence of lower limb varus or valgus the patient lies supine with the knees extended. The practitioner takes hold of the ankles and brings the legs together. If
198
SYSTEMS EXAMINATION
A
B
Figure 8.25 Assessment of motion at the IPJs A. Plantarflexion of the proximal IPJ B. Plantarflexion at the distal IPJ C. Dorsiflexion at the distal IPJ.
c
there is a difference of more than 5 cm between the knees genu varum is suspected; if it is impossible to bring the malleoli together a genu valgum is present (Beeson 1999). Obesity may prevent the knees and malleoli being brought together. Malleolar torsion. Torsion of the leg can affect the position of the foot, adducted (in-toe) and abducted (out-toe), as well as the position of the patellae. Assessing the amount of tibial torsion clinically is impossible, but it is suggested in the literature that assessing the relationship of the tibia and fibula malleoli to each other gives an indication of torsion in the leg (Hutter & Scott 1949, Lang & Volpe 1998). To measure malleolar torsion the patient lies in a supine position with the legs extended on the couch. The femoral condyles should lie in the frontal plane (i.e. par-
allel to the couch). The practitioner bends down until her eyes are level with the malleoli and observes the relationship of the malleoli to each other. The amount of malleolar torsion can be measured in three ways: • Estimate by using the thumb technique. Place the thumb of each hand anterior to the malleoli; the medial malleoli should be one thumb's thickness anterior to the lateral malleoli. • Traciograph. The protractor end of the tractograph should be held on the fibula side; one arm of the tractograph is placed parallel to the couch and the other arm is moved until it bisects the malleoli. • Gravity goniometer. The ends of the arms of the gravity goniometer are placed on the malleoli and the goniometer is held vertical (Fig. 8.26).
ORTHOPAEDIC ASSESSMENT
When the techniques were examined, the gravity goniometer fared best (Hayles & Lang 1987). Recent work suggests that there is good agreement between the gravity goniometer and CT scan measurements (Lang & Volpe 1998): 13-18° of malleolar torsion is considered normal. Tibial torsion is considered to be 5° more than malleolar torsion (Elftman 1945, Lang & Volpe 1998), therefore normal tibial torsion is 18-25°. Forefoot to rearfoot alignment. The plantar plane of the forefoot should lie parallel to the plantar plane of the rearfoot (Fig. 8.27B). The relationship of the forefoot to the rearfoot is
199
assessed by placing the foot in its neutral position; the patient may be either supine or prone but it is important that the foot hangs free of the couch. The neutral position of the foot is defined as the foot being neither pronated or supinated. To put the foot into the neutral position the practitioner should feel on the dorsum of the foot for the talar head. The foot should be moved into pronation and supination; while the foot is pronating the talar head can be felt protruding on the medial side of the talonavicular joint and while the foot is supinating it can be felt protruding on the lateral side of the talonavicular joint (Fig. 8.28). Neutral position is achieved when the talar head cannot be palpated on either side. As the foot is non-weightbearing it is also necessary to 'lock' the midtarsal joint in order to reproduce the position the foot would adopt if it were weightbearing. In order to lock the midtarsal joint the talar head should be held in its neutral position and a slight dorsiflexing force applied to the fourth and fifth met heads until the foot is at 90° to the leg. The neutral position of the foot therefore acts as a reference point from which joint motion and the position of parts of the foot can be assessed. While the foot is held in its neutral position a tractograph or a forefootmeasuring device can be used to measure any deviation of the forefoot to the rearfoot in the frontal plane; the forefoot may be inverted or everted to the rearfoot (Fig. 8.27C,A). Minor differences between the forefoot and rearfoot are usually insignificant and are often due to examiner error, but quite high angles of discrepancy can exist in excess of 15°. An inverted forefoot may be due to:
• True forefoot varus: bony abnormality,
Figure 8.26 goniometer.
Assessing malleolar torsion using a gravity
theoretically due to inadequate torsion of the head and neck of the talus during fetal development, but this is not well supported (Kidd 1997). The presence of a true forefoot varus is said to lead to a very flat foot with no longitudinal arch (Grumbine 1987). • Forefoot supinatus: acquired soft tissue deformity due to abnormal pronation of the rearfoot. The forefoot is held in an inverted position because of soft tissue contraction.
200
SYSTEMS EXAMINATION
Medial
A
Lateral
Medial
Forefoot valgus (everted 1-5)
Medial C
Lateral
Forefoot (1-5) parallel: rearfoot
B
Lateral
Forefoot varus (inverted 1-5)
Figure 8.27 Assessment of forefoot to rearfoot relationship A. Everted forefoot: the forefoot is everted to the rearfoot B. Ideal forefoot to rearfoot relationship: the forefoot is parallel to the rearfoot C. Inverted forefoot: the forefoot is inverted to the rearfoot.
This condition can be reduced with treatment. It can be difficult to differentiate between a forefoot supinatus and forefoot varus. Various techniques are suggested. One is to get the patient to stand; the foot is put into its neutral position. With both conditions
the medial side of the foot should not be in ground contact. Pressure is applied to the dorsum of the first ray: with a supinatus, there should be some give and the first ray should plantarflex; with forefoot varus, any pressure on the dorsum of the first ray
ORTHOPAEDIC ASSESSMENT
201
-------------------------_._-_.
A
B
Figure 8.28 Finding subtalar joint neutral A. Locating the talar head on the medial side B. Locating the talar head on the lateral side. It is easier to palpate the talar head on the lateral side than it is on the medial side.
should cause the foot to tilt inwards and the fifth ray to leave ground contact.
• Dorsiflexed first ray (metatarsus primus eleoaius): may be a fixed or flexible deformity.
• Plantarflexed fifth ray: as with the first ray this may be a fixed or flexible deformity dependent upon the cause, treatment may reduce the deformity. An everted forefoot may be due to:
• Forefoot valgus: bony abnormality, theoretically due to excessive torsion of the head and neck of the talus during fetal development which holds the forefoot in a fixed everted position that cannot be reduced with treatment. • Planiarjlexed first ray: a common cause of an everted forefoot position that may be due to a fixed or flexible deformity. • Dorsiflexed fifth ray: as with the first ray this may be a fixed or flexible deformity. The incidence of metatarsus primus elevatus and plantarflexed first ray is thought to be greater than that of forefoot varus and valgus. There may also be malalignment between the forefoot and the rearfoot in the sagittal and transverse planes. The forefoot may appear plantarflexed in relation to the rearfoot or vice versa. This may be a flexible or fixed deformity and may lead to a pes-cavus-type foot. The forefoot may appear adducted on the rearfoot; this may be due to a metatarsus adductus or metatarsus primus adductus; non-weightbearing the lateral border of the foot appears banana-shaped with a metatarsus adductus.
Arch height. The shape and height of the longitudinal arch should be observed and compared to its position when weightbearing. Creasing of the skin in the arch of the non-weightbearing foot usually indicates that the foot is mobile and excessively pronates on weightbearing. Metatarsal formula. The metatarsal formula refers to the apparent length of the metatarsals. The second metatarsal is usually the longest and the fifth the shortest. A typical metatarsal formula is 2 > 1 > 3 > 4 > 5 or 2 > 3 > 1 > 4 > 5. It is important that the first metatarsal is shorter than the second in order to allow normal function during propulsion. When the first MTPJ dorsiflexes the first ray plantarflexes on to the sesamoids; if the first metatarsal is as long as the second this cannot occur and as a result the first MTPJ is not able to dorsiflex, resulting in overloading of the other metatarsal heads, commonly the second. The practitioner should look at the shoe crease to observe the normal oblique angle afforded by the typical 2 > 1 > 3 > 4 > 5 formula. A rare but well-recognised formula is when the fourth metatarsal is congenitally short, known as brachymetatarsia (Tachdjian 1985). In this case the formula would be 2 > 1 > 3 > 5 > 4. The metatarsal formula is important for normal digital function. Abnormalities of the formula may affect forefoot pressure distribution, causing metatarsalgia. Short first metatarsals do not necessarily cause symptoms in the foot (Harris & Beath 1949); a correlation between long first metatarsals and the incidence of hallux abductus has been reported (Duke et al 1982). Minor changes in metatarsal length may not adversely affect forefoot function and weight distribution. Toe position. The position the toes adopt nonweightbearing should be noted and compared with the position they adopt weightbearing. Depending upon the effects of muscle pull and ground reaction, the extent of the deformity may reduce or increase on weightbearing. Foot length. The length and width of the foot should be measured non-weightbearing and compared with weightbearing measurements. Foot length and width should increase by a small amount when weightbearing; usually there is up to one or one and a half shoe size difference.
202
SYSTEMS EXAMINATION
However, noticeable differences in foot length (two to three shoe sizes) indicates a mobile foot which excessively pronates during gait. No differences between the two is indicative of a rigid foot.
STATIC EXAMINATION (WEIGHTBEARING) To complete the assessment, the patient should be observed standing. Information from this part of the assessment should help to complete the picture of lower limb alignment, give an indication of whether compensation is occurring at the STJ and enable deformities of the forefoot to be observed. It may be helpful to ask the patient to walk on the spot for a few steps and then tell him to stop. The position the patient adopts on stopping can be accepted as the normal angle and base of gait. As with gait analysis, the patient should be observed from head to toe. The following should be noted: • • • • • • • • •
head shoulders spine pelvis angle and base of gait relaxed and neutral calcaneal stance position longitudinal arch toes foot width and length.
Points related to the position of the head, shoulders and pelvis are the same as those made for gait analysis. Any abnormality may be indicative of an LU, neurological or spinal problem. The shape of the lower limb and distribution of muscle bulk should be noted. There should be symmetry of muscle bulk, although there may be slight variation between the dominant and recessive side of the body. This is particularly true where one side, arm and/or leg engages in a greater level of activity than the other. Spine
The position of the vertebrae should be observed for the presence of kyphosis, lordosis or scoliosis.
A true scoliosis can be differentiated from a functional scoliosis by asking the patient to bend forward. If the spine is still deviated when the hips are flexed a true scoliosis exists; if vertebrae alignment improves it is likely to be a functional scoliosis. Angle and base of gait
A normal angle and base of gait is when the feet are slightly abducted (approximately 13° from the midline of the body) and the distance between the malleoli is approximately 5 cm (see Fig. 8.4A). Frontal plane deformity of the legs genu valgum or va rum - may be very noticeable when the patient stands and will affect the base of gait, i.e. the gap between the malleoli will be greater (genu valgum) or less (genu varum) (see Fig. 8.5). The angle of gait will be affected by torsional problems affecting the leg. Excessive internal torsion will lead to an adducted base of gait and squinting patellae, whereas excessive external rotation will lead to an abducted base of gait (greater than 13°) (Fig. 8.4B-D). Torsional problems may be due to bony or soft tissue problems; the true cause should be identified from the nonweightbearing assessment. Relaxed (RCSP) and neutral (NCSP) calcaneal stance position
The relaxed calcaneal position is an indicator of STJ motion when weightbearing. This position can be used to assess whether compensation for any proximal (e.g. tibial varum) or distal (e.g. forefoot varus) deformities has taken place at the STJ. The RCSP is measured by bisecting the posterior surface of the calcaneus; the angle this line makes with the ground is measured (Fig. 8.29A). The amount of calcaneal eversion or inversion (frontal plane) can be measured. Values greater than 4° eversion indicate the presence of abnormal pronation: • 0-4°: normal limits • 4-7°: moderate pronation requiring treatment if symptomatic or a cause for concern • 8° and above: marked pronation.
ORTHOPAEDIC ASSESSMENT
The causes of an abnormal everted RCSP are numerous, e.g. compensated forefoot varus, compensated ankle equinus, tibial valgum and varum, internal and external torsion of the leg. If the calcaneus does not have an everted position during RCSP it does not mean that abnormal pronation is not occurring. Compensation for a rearfoot varus involves excessive STJ pronation in order to bring the medial tubercle of the heel into ground contact and provide shock absorption during the contact phase of gait. A 10° rearfoot varus will require 10° of pronation in order to bring the heel into a verti-
A
203
cal position. Although excessive pronation has occurred, the RCSP will appear vertical and not everted. An inverted RCSP may be due to a neurological problem, an uncompensated varus deformity affecting the rear- or forefoot, subtalar joint damage, tonic spasm of the invertors of the foot or the presence of a plantarflexed first ray. The NCSP is measured by placing the foot into its neutral position while in ground contact and bisecting the calcaneus (Fig. 8.29C). The angle between the bisection of the posterior surface of the calcaneus and the ground should be mea-
B
Figure 8.29 Assessment of RCSP and NCSP A. Feet in relaxed calcaneal stance position (RCSP) B. Bisection of the posterior surface of the calcaneus and the distal third of the leg C. Foot held in the neutral position in order to assess neutral calcaneal stance position (NCSP).
C
204
SYSTEMS EXAMINATION
sured; usually the calcaneus is in a slight inverted position. This is known as rearfoot varus and may be due to the presence of a subtalar varus (see non-weightbearing assessment of the STJ) and/ or tibial varum. The presence of a tibial va rum can be assessed during assessment of the NCSP. While the foot is in NCSP a bisection of the posterior surface of the leg should be compared to the ground. Ideally the bisection of the leg should be vertical to the ground (Fig. 8.29B). An angle of less than 90° when measured from the medial side of the bisection of the leg indicates a tibial valgum and an angle greater than 90° indicates a tibial varum. It was thought that the NCSP position was a composite of the STJ plus the tibial position. For example, a value of 7° rearfoot varus might be deemed to be made from 4° STJ varus and 3° tibial varum. A tibial valgum would conversely have a negative effect upon the presence of an STJ varus. Because of the inaccuracy and error in measuring these values, however, this concept is questionable. It is important to note the difference between the RCSP and NCSP in order to assess the compensation that occurs for proximal or distal problems (Fig. 8.29A,C). It is normal for there to be a difference of up to 6° between RCSP and NCSP; this is because most people have a slight subtalar varus and need to pronate to provide shock absorption. The limitations of comparing NCSP with RCSP is that it only provides information regarding frontal plane motion of the rearfoot. Some authors suggest that sagittal plane motion (Mueller et al1993, Payne & Dananberg 1997) or transverse plane motion (Nawoczenski et al 1995) may be a better indicator of foot pronation. Longitudinal arch
Arch shape is affected by the rearfoot and forefoot position, the declination angles of the metatarsals, the inclination angle of the calcaneus and the tone and activity of intrinsic and extrinsic muscles. In the past flat-footed people were rejected for the army as it was considered that their feet would not cope with the demands of
army life. However, there is rather more to foot function and mechanics than the height and shape of the longitudinal arch. The patient should be asked to stand on tiptoe and the position of the foot arch should be noted. With rigid flat feet the arch height does not increase when the patient stands on tip toe; with a flexible flat foot the arch height increases. Rigid flat feet may be due to bony coalitions (synostoses), contractures due to muscle imbalance or neurological paralysis with subsequent soft tissue contractures. The shape and size of the arch can be captured by taking a footprint; this can be used to monitor changes. Toes There are three main categories of pathomechanical causes of lesser hammer toe syndrome. Flexor stabilisation. A contraction (hammering) of all the lesser toes with an associated adductovarus deformity of the fifth and sometimes fourth toes (quadratus plantae losing its mechanical advantage). This can occur in an excessively pronated foot during late stance phase when flexor digitorum longus and/or flexor digitorum brevis have gained mechanical advantage over the interossei muscles. Pronation of the STJ allows unlocking of the midtarsal joint, resulting in forefoot hypermobility. The flexors fire earlier and longer than normal in an attempt to stabilise the forefoot. These muscles are ineffective at stabilising the forefoot but effective in overpowering the small interosseous muscles, thereby causing hammering or clawing of the toes. Flexor substitution. A straight contraction of all the lesser toes (with no adductovarus of the fourth and fifth toes). This can occur in a supinated foot during late stance phase when the flexors have gained mechanical advantage over the interossei muscles. This digital deformity occurs when the triceps surae muscle is weak and the deep posterior and lateral leg muscles try to substitute for the weak triceps. Flexor substitution is the least common of the three categories that create pathological hammer toe syndrome of the lesser toes.
ORTHOPAEDIC ASSESSMENT
Extensor substitution. Extensor substitution is a term that describes the excessive dorsiflexion of the toes during swing phase of gait and at heel strike. Extensor digitorum longus (EDL) gains mechanical advantage over the lumbricales. This can be due to a variety of factors. An anterior pes cavus, ankle equinus, pain, spasticity of the EDL muscle or weakness of the lumbricales. Without the stabilising effect of the lumbricales the MTPJs will be excessively dorsiflexed, resulting in severe dorsal contraction of the toes. This is commonly seen in pes cavus during non-weightbearing (Fig. 8.30) and can be emphasised by asking the patient to dorsiflex the foot. It is exaggerated during the swing phase of gait and at heel contact when extensor digitorum longus and brevis are normally active. This deformity often begins as a flexible deformity that may reduce completely during weightbearing but becomes more rigid as accommodative contractures develop. Hallux abductus and hallux abductovalgus are common complex deformities affecting the first MTPJ (Fig. 8.31). Slight abduction of the hallux is considered normal, up to 15°. Deviation of the hallux can be measured with a finger goniometer: the value should be recorded so that deterioration of the condition can be monitored. The fifth ray may frequently be abducted: tailor's bunion or digiti quinti varus may be associated with hallux abductus, giving a splayed
Figure 8.30 Flexed deformity of toes (28-year-old male) due to extensor substitution present on non-weightbearing and weightbearing.
205
and therefore broad forefoot appearance. Changes in forefoot shape due to hallux abductus and digiti quinti varus can be monitored by taking photographs or ink prints of the foot on a regular (twice-yearly) basis. It is also useful to draw around the foot at regular intervals to gain a visual representation of foot shape and to monitor changes.
Figure 8.31 Hallux abductovalgus: abduction of the hallux with valgus rotation.
206
SYSTEMS EXAMINATION
Digital formulae should be noted. Usually the first toe is longest or the first and the second are of equal length - 1 > 2 > 3 > 4 > 5, 1 = 2 > 3 > 4 > 5. An excessively long toe, e.g. the fourth, may be impacted in footwear, resulting in toe deformity and secondary lesions. Deformities of the lesser digits (toes 2-5) can be described in various ways; unfortunately, there is no commonly agreed set of definitions. When assessing and recording the presence of digital deformities, the best approach is to describe the plane that the deformity is in - e.g. sagittal - and whether the deformity is fixed or mobile. A fixed deformity implies that there is no motion at the joint due to soft tissue changes and possible bony ankylosis; such deformities can only be corrected by surgery. Table 8.9 lists and defines the main toe deformities.
Table 8.9
Classification of toe deformities
Toe deformity
Description
Hallux abductus
Hallux abducted more than 15° from the midline of the body
Hallux abductovalgus
As above, but the hallux is also rotated so that the hallux nail faces towards the midline of the body
Hallux abductus interphalangeus
Distal hallucal phalanx abducted away from the midline of the body
Hallux varus
Hallux adducted towards the midline of the body
Hallux limitus
Reduced dorsiflexion at the first MTPJ
Hallux rigidus
Complete lack of dorsiflexion at the first MTPJ
Hallux flexus
Plantarflexion of the hallux at the first MTPJ
Hallux extensus
Dorsiflexion of the hallux at the first MTPJ
LIMB-LENGTH INEQUALITY
Hyperextended hallux
Distal phalanx of the hallux dorsiflexed
Once gait analysis, non-weightbearing and static weightbearing examinations have been completed it may be necessary to assess for limblength inequality. An LLI can have profound effects on the functioning of the musculoskeletal system, affecting the spine, sacroiliac and hip joints as well as the foot. A difference of greater than 1 cm can affect normal body alignment. In a sedentary person a small discrepancy may have a negligible effect upon posture, but if a person increases his level of physical activity, the effects of any imbalance become amplified. A leg-length discrepancy may be real, apparent or environmental. A real limb-length discrepancy is due to a difference in the length of the femurs or the tibiae and is common after a hip replacement. An apparent limb-length discrepancy may be due to a number of factors, e.g. osteoarthritis of the hip or a scoliosis. In addition, an environmental limb-length discrepancy may exist; this can be due to uneven footwear or camber of roads. It is important to identify the difference in length between the limbs and to differentiate between a real and apparent discrepancy prior to commencing treatment. It should be noted that a real and an apparent limb-length inequality may
Hammer toe
Dorsiflexion at the MTPJ, plantarflexion at the proximal IPJ and either normal position or dorsiflexion at the distal IPJ
Claw toe
Dorsiflexion at the MTPJ, plantarflexion at the proximal and distal IPJs
Retracted toe
Claw toe where the apex of the toe is not in ground contact
Mallet toe
Plantarflexion at the distal IPJ
Adductovarus fifth
Fifth toe rotated so that nail is facing away from the midline of the body and the toe is adducted (moved towards the midline of the body)
Dorsally displaced
One or more toes is in a dorsiflexed position in comparison to the other toes
coexist. The possible effects of treatment should be considered prior to commencing treatment (Case comment 8.6). The presence of a limb-length discrepancy can be observed during gait analysis: • shoulder tilt to one side • unequal arm swing • pelvic tilt
ORTHOPAEDIC ASSESSMENT
207
Case comment 8.6 .:
It should be remembered that a patient who has had a discrepancy for years will have compensated by altering his/her body posture. If any raise under the heel is considered, this must only be for a proportion of the difference. Heel raises used alone may cause unwanted plantar flexion, especially when the deformity is greater than 2.5 em. The adaptation to footwear should affect the whole sole in this case.
• • • •
foot supinated on the short side foot pronated on the long side knee flexed on the long side ankle plantarflexed on the short side.
Limb length measurement is only performed if the patient's symptoms or dynamic function suggest that a discrepancy may be present. To assess for the presence of a real LLI the patient lies supine on a flat couch with the hips and knees extended. The practitioner places her hands around the heels and exerts a slight pull on the legs, at the same time bringing the legs together so that the knees and malleoli are touching. The knees and malleoli should be level. A difference indicates an inequality at the femur or tibia. To identify which bone is affected the knees should be flexed and the heels pushed flush against the buttocks (Skyline/Allis test) (Fig. 8.32). If the tibiae are of unequal length, the knees or tibial tubercles will be at different levels. If one femur is longer than the other, the knee of the longer femur will be positioned further forward than the other knee. This is a relatively crude method of assessment and does not quantify the extent of the difference. A flexible non-stretch tape measure with a metal end can be used to measure a real leg length ('direct measurement technique'). With the patient supine the distance between the anterior superior iliac spine (ASIS) and the medial malleolus is measured (Crawford Adams & Hamblen 1990). The metal end of the tape fits snugly in front of the ASIS, as shown in Figure 8.33A. The practitioner may use any part of the medial malleolus as a reference point, but it is important that the same point is used for repeat measurements. An error of up to 10%
Figure 8.32 Assessment of leg-length inequality.The knees are flexed so that the position of the knees and ankles can be compared.
should be allowed for because the tape measure may wrap around asymmetrical muscle bulk or, more commonly, the patient's pelvis may not be properly aligned. In cases of asymmetrical muscle bulk, measuring from the ASISs to the lateral malleoli is advocated. A tape measure can be used to compare the individual lengths of the femurs by measuring from the greater trochanter to the lateral knee joint line. The lengths of the tibiae can be compared by measuring from the medial knee joint line to the medial malleolus or the tibial tubercle to the middle of the anterior ankle. The 'indirect measurement technique' can also be used to assess a real leg length. The patient stands while blocks of wood of varying thicknesses are placed under the suspected shorter limb until the iliac crests are palpated to be level. Radiological measurement (Scannergram) is only used when surgical correction is planned, as it is expensive and, unless the results are going to
208
SYSTEMS EXAMINATION
be used for surgery, exposes the patient to needless radiation. Distinction between a real or apparent difference can be achieved by measuring each limb from a common reference point above the pelvis; the xiphisternum is usually used. The metal end of the tape is placed on the xiphisternum and the distance from the xiphisternum to each malleolus is measured with the patient (Fig. 8.33B). If values are the same, then the LLI is likely to be apparent. The cause usually lies at the hip or pelvis, where a fixed deformity makes the limbs appear unequal so that the body compensates by tilting laterally. An alternative method can be used with the patient weightbearing:
• The patient stands in the RCSP position (Fig. 8.29A). • The position of the ASISs is assessed to see if they are level. • The feet are then placed in the NCSP (Fig. 8.29C). • The position of the ASISs is assessed to see if they are level. • If the ASISs are not level in either the RCSP and NCSP, and the extent of the discrepancy remains the same in RCSP and NCSP, a true LLI should be suspected. If the ASISs are on the same level in the NCSP but differ for the RCSP, an apparent LLI should be suspected.
B Positioning for xiphisternum
Figure 8.33 Assessment of a true and apparent leg-length inequality A. Measurement from the anterior superior iliac spine (ASIS) to the medial malleolus B. Measurement from the xiphisternum to the medial malleolus.
ORTHOPAEDIC ASSESSMENT
SUMMARY Orthopaedic assessment of the lower limb is a complex process. Good observational skills, an ability to take a detailed history and an holistic approach to examination are paramount. It can be compared to doing a jigsaw - all the pieces have to be put together in order to produce the picture. Because the lower limb functions as one mechanical unit, it is important that the practitioner differentiates between primary and
209
any secondary problems. However, it is not always necessary to examine every component of the lower limb. The practitioner should weigh up the necessity for a head to toe examination against assessing isolated parts of the anatomy. This decision will be informed by data obtained from the patient's history, the presenting problem, a brief gait analysis and information from other parts of the assessment process.
REFERENCES Astrom M, Arvidson T 1995 Alignment and joint motion in the normal foot. Journal of Orthopedic Sports Physical Therapy 22(5): 216-222 Barnett C H, Napier J R 1952 The axis of rotation at the ankle joint in man. Its influence upon the form of the talus and the mobility of the fibula. Journal of Anatomy 86: 1-9 Beeson P 1999 Frontal plane configuration of the knee in children. The Foot 9(1): 18-26 Bojson-Moller F 1979 Anatomy of the forefoot - normal and pathological. Clinical Orthopaedic Related Research 142: 10-18 Brukner P, Khan K 1993 Clinical sports medicine. McGraw Hill, Sydney, p 438 Buckley R E, Hunt D V 1997 Reliability of clinical measurement of subtalar joint movement. Foot & Ankle International 18(4): 229-232 Crawford Adams J, Hamblen D L 1990 Outline of orthopaedics, 11th edn. Churchill Livingstone, Edinburgh, pp 280-283, 353 Dananberg H L 1986 Functional hallux limitus and its relationship to gait efficiency. Journal of the American Podiatric Medical Association 76(11): 648-652 Dananberg H L 1993 Gait style as an etiology to chronic postural pain. Part 1: functional hallux limitus. Journal of the American Podiatric Medical Association 83(8): 433--441 Duke H, Newman L M, Bruskoff B L, Daniels R 1982 Relative metatarsal length patterns in hallux abductovalgus. Journal of the American Podiatric Association 72: 1-5 Elftman H 1945 Torsion of the lower extremity. American Journal of Physical Anthropology 3: 255-265 Elftman H 1960 The transverse tarsal joint and its control. Clinical Orthopaedics 16 Elveru R A, Rothstein J M, Lamb R L 1988 Goniometric reliability in a clinical setting. Physical Therapy 68(5): 672-677 Gajdosik R L, Giuliani C A, Bohannon R W 1990 Passive compliance and length of the hamstring muscles of healthy men and women. Clinical Biomechanics 5(1): 23-29 Gajdosik R L, Rieck M A, Sullivan D K et al 1993 Comparison of four clinical tests for assessing hamstring muscle length. J Orthopaedic Sports Physical Therapy 18(5): 614-618 Green D R, Carol A 1984 Planal dominance. Journal of the American Podiatry Association 74: 98-103
Grumbine N A 1987 The varus components of the forefoot in flatfoot deformities. Journal of the American Podiatric Medical Association 77: 14-20 Harris R 1, Beath T 1949 The short first metatarsal: its incidence and clinical significance. Journal of Bone and Joint Surgery [Am] 31A(4): 553-565 Hayles M, Lang L 1987 Measuring tibial torsion: comparison of measurement techniques. ACTUK Journal Spring: 17-20 Hutter C G, Scott W 1949 Tibial torsion. Journal of Bone and Joint Surgery [Am] 31A: 511-518 Inman V T 1976 The joints of the ankle. Williams & Wilkins, Baltimore, p 65 Inman V T, Ralston H J, Todd F 1981 Human walking. Williams & Wilkins, Baltimore, pp 86-108 Kendall F P, Kendall-McCreary E, Geise-Provance P 1993 Muscles: testing and function, 4th edn. Williams & Wilkins, Baltimore, pp 68-77 Kelso S F, Ritchie D H, Cohen I R, Weed J H, Root M L 1982 Direction and range of motion of the first ray. Journal of the American Podiatry Association 72(12): 600-605 Kidd R 1997 Forefoot varus - real or false, fact or fantasy. Australian Journal of Podiatric Medicine 31(3): 81-86 Kilmartin T E, Wallace A, Hill T W 1991 First metatarsal position in juvenile hallux abductovalgus - a significant clinical measurement? Journal of British Podiatric Medicine 46: 43--45 Kulik S A, Clanton T 0 1996 Tarsal coalition. Foot & Ankle International 17(5): 286-296 Lang L M G, Volpe R G 1998 Measurement of tibial torsion. Journal of the American Podiatric Medical Association 88(4): 160-165 McRae R 1997 Clinical orthopedic examination, 4th edn. Churchill Livingstone, Edinburgh, pp 1-7 Menz H B 1995 Clinical hindfoot measurement: a critical review of the literature. The Foot 5(2): 57-64 Menz H B 1998 Alternative techniques for the clinical assessment of foot pronation. Journal of the American Podiatric Medical Association 88(3): 119-129 Milgrom C, Giladi M, Simkin A et al 1985 The normal range of subtalar inversion and eversion in young males as measured by three different techniques. Foot & Ankle International 5: 143-145 Miyazaki S, Yamamoto S 1993 Moment acting at the metatarsophalangeal joints during barefoot level walking. Gait Posture 1: 133-140
210
SYSTEMS EXAMINATION
Mueller M J, Host J V, Norton B J 1993 Navicular drop as a composite measure of excessive pronation. Journal of the American Podiatric Medical Association 83(4): 198-202 Nawoczenski D A, Cook T M, Saltzman C L 1995 The effect of foot orthotics on three-dimensional kinematics of the leg and rearfoot during running. Journal of Orthopaedic Sports Physical Therapy 6: 317-327 Payne C B, Dananberg H J 1997 Sagittal plane facilitation of the foot. Australian Journal of Podiatric Medicine 31(1): 7-11 Riegger-Krugh C, Keysor J J 1996 Skeletal malalignments of the lower quarter: correlated and compensatory motions and postures. Journal of Orthopaedic Sports Physical Therapy 23(2): 164-170 Rome K 1996a ankle joint dorsiflexion measurement studies - a review of the literature. Journal of the American Podiatric Medical Association 86(5): 205-211 Rome K 1996b A reliability study of the universal goniometer, fluid goniometer, and eletrogoniometer for the measurement of ankle dorsiflexion. Foot & Ankle International 17(1): 28-32 Root M L, Weed J H, Sgarlato T E, Bluth D R 1966 Axis of motion of the subtalar joint. An anatomical study.
Journal of the American Podiatry Association 56: 149-155 Spooner S K, Kilmartin T E, Merriman L M 1994 The palpation technique for determination of metatarsal formula: a study of validity. The Foot 4(4): 198-200 Sutherland D H et al1981 The pathomechanics of gait in Duchenne muscular dystrophy. Development of Medicine & Child Neurology 23(3): 3-22 Svenningsen S, Terjesen T, Auflem M, Berg V 1990 Hip rotation and in-toeing gait. A study of normal subjects from four years until adult age. Clinical Orthopaedics & Related Research 251: 177-182 Tachdjian M 01985 The child's foot. W B Saunders, Philadelphia Thackery C, Beeson P 1996 In-toeing gait in children: a review of the literature. The Foot 6(1): 1--4 Tiberio D, Burdett R G, Chadran A M 1989 Effect of subtalar joint position on the measurement of ankle dorsiflexion. Clinical Biomechanics 4: 189-191 Tomaro J 1995 Measurement of tibiofibular va rum in subjects with unilateral overuse syndromes. Journal of Orthopaedic Sports Physical Therapy 21(2): 86-89
FURTHER READING Altman M 11968 Sagittal plane angles of the talus and calcaneus in the developing foot. Journal of the American Podiatry Association 58: 463--470 Anderson J A D, Sweetman B J A 1975 Combined flexirule/hydrogoniometer for measurement of lumbar spine and its sagittal movement. Rheumatology & Rehabilitation 14: 173-179 Apley A G, Solomon L 1988 Concise system of orthopaedics and fractures. Butterworths, London Bailey D S, Perillo J T, Forman M 1984 Subtalar joint neutral. A study using tomography. Journal of the American Podiatry Association 74: 59-64 Bartlett M D, Wolf L S et al1985 Hip flexion contracture measurements. Archives of Physical and Medical Rehabilitation 66: 620-625 Bland J M, Altman D G 1986 Statistical methods for assessing agreement between two methods of clinical measurement. Lancet February: 307-310 Cochran G, Van B 1982 A primer of orthopaedic biomechanics. Churchill Livingstone, New York Coughlin M J, Mann R A 1999 Surgery of the foot and ankle, 7th edn. Mosby, St Louis D' Amico J C, Schuster R 01979 Motion of the first ray clarification through investigation. Journal of the American Podiatry Association 69: 17-23 Ebesui J M 1968 The first ray axis and first metatarsophalangeal joint. An anatomical and pathological study. Journal of the American Podiatry Association 58: 160-167 Fabry G, MacEwan G D, Shands A R 1973 Torsion of the femur. A follow up study in normal and abnormal conditions. Journal of Bone and Joint Surgery [Am] 55A: 1726-1738 Fairbank J C T, Pynsent P B, Van Poortvliet J, Phillips H 1984 Mechanical factors in the incidence of knee pain in adolescents and young adults. Journal of Bone and Joint Surgery [Br] 66B: 685-692
Green W B, Heckman J D (eds) 1993 The clinical measurement of joint motion. American Academy of Orthopaedic Surgeons, Illinois Green D R, Whitney A K Walters P 1979 Subtalar joint motion. A simplified view. Journal of the American Podiatry Association 69: 83-91 Hartley A 1995 Practical joint assessment: lower quadrant. Mosby, St Louis Helal B, Gibb P 1987 Freiberg's disease: a suggested pattern of management. Foot and Ankle 8(2): 94-102 Henry A P J, Waugh W 1975 The use of footprints in assessing the results of operations for hallux valgus - a comparison of Keller's operation and arthrodesis. Journal of Bone and Joint Surgery [Br] 57-B: 478--481 Hicks J H 1953 The joints. The mechanics of the foot. Journal of Anatomy 87 Holden M K et al1984 Clinical gait assessment in the neurologically impaired. Reliability and meaningfulness. Physical Therapy 64: 35--41 Kelso S F, Richie D H, Cohen I R et al 1982 The direction and range of the first ray. Journal of the American Podiatry Association 72: 600-605 Mann R, Inman V T 1964 Phasic activity of intrinsic muscles of the foot. Journal of Bone and Joint Surgery [Am] 46A: 469--481 McGlarnry E D 1992 Lesser ray deformities. In: McGlarnry E D, Banks A S, Downey M S (eds) Comprehensive textbook of foot surgery, 2nd edn. Vol. 1. Williams & Wikins, Baltimore Manter J T 1941 Movement of the subtalar and transverse tarsal joints. Anatomy Records 80: 397--410 Myerson M S, Shereff M J 1989 The pathological anatomy of claw and hammer toes. Journal of Bone and Joint Surgery [Am] 71A: 45--49 Norkin C C, White D J 1995 Measurement of joint motion: a guide to goniometry, 2nd edn. F A Davis, Philadelphia
ORTHOPAEDIC ASSESSMENT
Scott J H 1983 In: Harris N (ed) Leg length inequality, a postgraduate textbook of clinical orthopaedics. Blackwell, Oxford, pp 282-291 Sgarlato T E 1973 A compendium of podiatric biomechanics. California College of Podiatric Medicine Subotnick S I 1979 Cures for common running injuries. Anderson World, California Sussman R E, Piccora R 1985 The metatarsal sesamoid and
211
first metatarsophalangeal joint. Journal of the American Podiatric Medical Association 75: 327-330 Welton E A 1992 The Harris and Beath footprint: interpretation and clinical value. Foot and Ankle 13: 462--468 Whittle M 1991 Gait analysis. An introduction. Butterworth Heinemann, Oxford Williams P L, Warwick R (eds) 1989 Gray's anatomy, 36th edn. Churchill Livingstone, Edinburgh
CHAPTER CONTENTS Introduction 213 Approach to the patient 213 Psychological aspects of skin disease 214 The purpose of assessment 214 How common is skin disease? 214
Assessment of the skin and its appendages 1. Bristow R. Turner
Skin structure and function 215 Epidermis 216 Dermo-epidermaljunction 217 Dermis 218 Skin appendages 218 )
History and examination of the skin 219 History taking 219 Clinical examination 220 Common tests and investigations 227 Recording of the assessment 228
INTRODUCTION
Hyperkeratoticdisorders 229 Assessment of corns and callus 229 Blistering disorders 231 Inflammatoryconditions of the skin 232 Eczema 232 Psoriasis 233 Vasculitis 234 Lichen planus 234 Granulomaannulars 235 Necrobiosis Iipoidica 235 Other inflammatory conditions 235 Allergies and drug reactions 235 infections of the skin 236 Viral 237 Bacterial 237 Fungal 238 Infestationsand insect bites 238 Disorders of subcutaneoustissue Systemic disorders and the skin Pigmented lesions 240 Skin tumours 242 Benign tumours 242 Malignanttumours 242 Summary 243
239 239
Dermatology is the study of the skin and its disorders. More than just an inert barrier, the integument is a highly active organ with an important role in physiology and homeostasis. There are over 5000 recognised skin disorders in existence but the largest percentage of skin disease is due to a handful of conditions, which may range from the trivial (i.e, minor bruising) to life threatening (i.e. malignant melanoma). Most skin diseases do not have a significant mortality, although they cause significant morbidity and have a high impact on the quality of life of patients (Harlow et al 1998). Typically, skin disorders affect individuals in a number of ways (the four Ds): • • • •
discomfort: i.e, itching and pain disability: i.e. foot ulceration, hand eczema disfigurement: i.e. scarring or rashes death: i.e. skin cancers.
APPROACH TO THE PATIENT The key to a good dermatological assessment is, firstly, a thorough history. This provides essential information and initiates an understanding of the patient as a person, the environment and an appreciation of the psychological aspects to the skin disease. The second stage is examination of the skin (with investigations when required). The skin is an easily accessible structure, but it is frequently difficult for non-dermatologists to examine and record their findings. Therefore a 213
214
SYSTEMS EXAMINATION
basic orderly approach is required if a successful outcome is to be achieved.
Psychological aspects of skin disease The skin defines who we are and how we are perceived to be. It is on our appearance we are judged by others (Lawton 2000). One only has to see the amount of time and money invested in changing or enhancing our appearance to appreciate how important the skin and its appendages are. A common mistake of students when faced with a patient with widespread skin disease is to remain at a distance, avoiding any physical contact. Skin diseases are subconsciously often perceived as nasty, dirty or infectious. As a practitioner, preconceptions need to be overcome if the patient is to be reassured that they are in the care of an empathetic, understanding professional. It should be remembered that the problems of the skin patient may be more than skin deep, even with conditions that are perceived by the practitioner to be trivial. Many patients suffering the most common skin disorders such as psoriasis and eczema have a quality of life similar to patients with other chronic diseases such as rheumatoid arthritis, cancer and heart disease. Often, the visibility of skin lesions to others is not correlated to the sufferer's well-being (Fortune et al 1997) and many conditions may be aggravated by psychological stress, i.e. atopic dermatitis, psoriasis and lichen planus. It should also be borne in mind that often just acknowledgement and discussion of the wider problems with a patient, in a sensitive and empathetic manner, is an important aspect of the assessment (Case history 9.1).
THE PURPOSE OF ASSESSMENT The assessment procedure is at the heart of the diagnostic and treatment process. From a patient's perspective assessment is seen as the reaching of a diagnosis and arriving at a decision on the most suitable form of treatment, i.e. what it is and what can be done about it. Most patients' fears regarding skin disease revolve around
----.---------------._--_ _--..
Case history 9.1 Mrs F is a 50-year-old housewife with a 35-year history of widespread psoriasis. With no family history, she developed the disease in her teens. This made normal activities such as socialising and relationships impossible due to the widespread disease and its appearance. Every day, Mrs F has to spend 2 hours applying emollients and other medicaments that are often greasy and for most would be intolerable. Excessive washing of clothes and bed linen, as well as cleaning around the house, are everyday tasks due to the exfoliative nature of the disease. With time, Mrs F has undergone many forms of treatment for her condition, with limited success, but with the help and support of her family and health professionals she has developed her own coping strategy.
issues such as 'is it catching?' and 'will it get better?'. All the information gathered during the assessment will help to inform and reassure the patient accordingly. The difficulty is that many skin diseases, to the untrained eye, appear very similar. The second challenge is deciding whether the skin disease is part of an underlying systemic condition; therefore, the importance of the whole assessment process cannot be overstressed. Many underlying conditions may be reflected in the condition of the skin and nails. For example, clubbing of the nails is a feature often associated with smokers and those with lung disease. Recurrent ulceration and infection of the foot is a common diagnostic marker in diabetes mellitus. Recognising such features will improve the likelihood of a successful diagnosis and treatment plan.
How common is skin disease? Reliable data are difficult to obtain but skin disorders are thought to affect around a quarter of the population, with only a small percentage seeking professional help. Typically, 10-20% of a general practitioner's annual workload involves skin disorders (Office of Population Census and Surveys 1991), and podiatrists also spend a significant amount of time treating skin conditions (i.e. hyperkeratosis, nail disorders and wounds, etc.).
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
Table 9.1
Of the most common disorders, most can affect the lower limb (Gawkrodger 1992): • • • • •
fungal and other skin infections dermatitis/eczema psoriasis warts tumours (benign and malignant).
Functions of the skin
Functions of the skin
Specific property
Barrier properties
Physical: thermal/mechanical/ radiation Chemical: irritants/allergens/ water loss Microbiological: infections/ infestations
Sense organ
Touch/vibration/pressure/ temperature Nociception
Other
Thermoregulation and assistance in maintaining blood pressure Vitamin D and cholesterol production
SKIN STRUCTURE AND FUNCTION The skin (or integument) is the largest organ system and covers around 1.8 m 2 • Much more than just an inert wrapping, the skin is a highly active organ that fulfils many functions (Table 9.1) which are determined by its structure. The skin comprises three layers: an epithelium (epidermis) and a connective tissue matrix (the dermis) firmly bound together at the dermoepidermal junction (Fig. 9.1); below the dermis lies the subcutaneous (fat) layer.
Across the whole body surface, there are considerable regional variations in the skin's structure, which in turn dictates its specific properties. These local variations may then influence the microclimate and therefore the pattern of organisms. Such variation may also
' t - - - - - - Hair
Skin surface
Epidermis ))------::::- Sweat duct Hair follicle -------'((11\--11Erector pili muscle - - - - - - - " ' \
Dermis
Hair bulb has a ----, rich vascular supply
-\
~
Sebaceous gland
~ Eccrine gland
Apocrine gland
Figure 9.1
215
Normal skin (not to scale) showing epidermis and dermis and the skin appendages, excluding nail.
216
SYSTEMS EXAMINATION
account for the typical distribution of skin disease.
Epidermis The epidermis (Plate 9) is an avascular structure, relying on the diffusion of materials across the dermo-epidermal junction for nutrients and waste disposal. It is principally composed of keratinocytes (corneocytes), which make up approximately 80% of the cells, as well as melanocytes, Merkel's discs and Langerhans' cells. Appendages of the epidermis include the nails, sweat glands and sebaceous glands (Fig. 9.1). The epidermis can range in thickness from around 0.4 to 1.5 mm, depending on the anatomicallocation; it is divided into four layers. Basal layer (stratum germinativum). For the most part, the basal layer consists of a single, undulating layer of cuboidal keratinocytes. The cells within this layer are firmly attached to the dermo-epidermal junction (OED by tonofilaments which arise from the cytoplasm of the cells linking into the hemidesmosomes anchored into the DEJ (Venning 2000). These mitotically active cells generate the cells of the more superficial layers of the epidermis. Scattered throughout this layer are specialist cells known as melanocytes. In sun-exposed areas (e.g. the face) they may have a ratio of 1 in 4, whereas on unexposed areas such as the plantar surface of the foot their numbers may decrease to 1 in 30. These cells are well developed in the epidermis of humans as we have a relatively hairless integument. Melanocytes are dendritic cells which produce a pigment melanin in specialist organelles known as melanosomes. These melanin granules then pass along the dendritic processes of the cell and are distributed evenly to adjacent keratinocytes. The melanin forms a protective cap over the cell nucleus, its function being to limit the amount of harmful ultraviolet radiation reaching the DNA within the nucleus. Recently, it has been proposed that melanin also has a role in mopping up free radicals, which arise as a result of inflammation within the skin (Norlund 1994). The amount of melanin produced across various races is roughly equal;
however, in darker skins the melanin granules are much more dense and less susceptible to degradation as they ascend through the epidermis. Merkel's cells are specialised nerve endings of unknown origin, possibly a modified keratinocyte (McKee 1996) found in the basal layer. Their function is thought to be the perception of light touch. They are typically only found in specific regions of the skin, being numerous on the volar (pulp) surfaces of the fingers and toes, in the nail beds and the dorsum of the foot. Prickle cell layer (stratum spinosum). The new cells generated by the active basal layer pass into the stratum spinosum. Here they become more polyhedral in shape. Internally, large numbers of keratin filaments (tonofilaments) surround the nucleus, whereas externally the cells have abundant spinous processes. These are desmosomes, bonding adjacent cells together, and are an important component of the epidermis, as they resist mechanical stress. In the upper part of this layer are the first lamellar granules. These secretory organelles contain many substances such as glycoproteins, phospholipids, sterols and lipases. Their significance is still being debated but it has been suggested that these granules are responsible for the barrier function found higher in the epidermis (Freinkel & Traczyck 1985). Langerhans' cells make up about 8% of the epidermis and are particularly found in the stratum spinosum. They are derived from bone marrow and are dendritic in structure, forming no apposition with the cells around them. Functionally, these cells are outposts of the immune system in the epidermis, recognising and presenting antigens to sensitised T lymphocytes and they have an important role in hypersensitivity and allergic reactions. Patients with specific skin diseases may have reduced numbers of Langerhans' cells. Granular layer (stratum granulosum). By the time the ascending cells have reached the granular layer they are much more flattened in appearance and are packed with keratohyalin granules. These granules are primarily composed of proteins and various types of keratins. As the cells move up towards the next layer of the epidermis the lamellar granules migrate to and fuse with
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
the cell membrane, expelling their contents into the intercellular space. The ejected lipid material is then organised into sheets at the junction with the stratum corneum. This forms a hydrophobic barrier (an almost watertight seal) along the junction of the two layers. In eczematous plaques, this process of extrusion is often reduced, leading to increased water loss through the epidermis and resultant fissuring (Cork 1997). Horny layer (stratum corneum). As the cell becomes cornified it loses a percentage of its water content and has a very flattened appearance with around 15-20 layers of keratinocytes. The remaining intracellular water accumulates, acting as a plasticiser with intracellular keratin, and causes the cell to swell. This improves the barrier seal to the epidermis and prevents fissuring of the skin under normal tensile forces (Cork 1997). Cells at this level begin a little understood pre-programmed cell death with most of the intracellular material undergoing breakdown, leaving just the keratin and protein matrix within these now cornified cells. Remnants of organelles and melanin pigment may be present within the stratum corneum. Normally, cells in this layer have lost their nucleus, but it may remain in incompletely keratinised cells (parakeratosis). The deeper cells in this layer are densely packed and so this area is often referred to as the stratum compactum (originally called the stratum lucidum). As cells ascend the stratum they continue to change. Modifications to the lipid membranes of the keratinocytes reduce adhesion, and so cells become less densely packed. There is also degradation of desmosomes, which further weakens cellular adhesions until the cells ascend to a level where desquamination is likely - the stratum dysjunctum. The skin as a barrier
The whole process of cell generation, maturation and degradation strives to create an effective barrier from water loss and from invading organisms, allergens or irritants. Many mechanisms are in place to help fulfil this function. However, the main threats to this barrier include trauma
217
(scratching, etc.), desiccation and hydration (Forslind 1994). Drying of the epidermis, central to many skin diseases, causes keratinocytes to shrivel and lose apposition, leading to fissuring, while excessive hydration strips the lipid barrier from the epidermis. Control of the keratinisation process
The epidermis can be considered an active organ, constantly generating keratinocytes in the basal layer which, in a period of 28-70 days, ascend through the superior layers, and undergo a cycle of maturation, keratinisation and desquamation. Regulation of this process is complex, but local factors within the epidermis, dermis and other tissues can modulate the rate of proliferation (i.e. inflammatory mediators in the dermis, tissue growth factors, fibroblasts, vitamin A derivatives, etc.). Disease processes may also disturb the normal equilibrium. Psoriasis often accelerates epidermal transit time to as little as 5 days, whereas skin carcinomas may trigger an uncontrolled proliferation of cell growth within the epidermis.
Derma-epidermal junction (DEJ) The point at which the dermis meets the epidermis is known as the dermo-epidermal junction. This is a basement membrane divided into a number of layers, crossed by a complex of filaments, keratins and proteins that form an anchoring surface between the dermis and epidermis. In areas of greater mechanical stress, to enhance adhesion the dermis makes regular finger-like folds into the overlying epidermis, known as dermal papillae. These are complemented by protrusions from the epidermis into the dermis, known as rete pegs or epidermal ridges. This undulation serves to increase the surface area of attachment and is a major feature of the plantar surface of the foot, where mechanical stresses can be high. Pathologically, the DEJ is the site of many pathologies and this can lead to loss of adhesion and the development of blistering diseases (i.e. epidermolysis bullosa, dermatitis herpetiformis).
218
SYSTEMS EXAMINATION
Dermis Below the dermo-epidermal junction lies the dermis. This consists essentially of dense fibroelastic connective tissues in a gel-like base (ground substance) which contains glycosaminoglycans. Collagen strands provide tensile strength, with elasticity afforded by interwoven elastic fibres that make this a pliable tissue. Accommodated within the dermis are the skin appendages, macrophages, fibroblasts and the neurovascular network. The thin, upper layer or papillary dermis contains most of the blood and lymphatic vessels, whereas the less vascular, deep reticular layer, is much more dense with collagen and elastic fibres. Cells of the immune system are present in the dermis, i.e. T lymphocytes and mast cells. Subcutaneous layer
The dermis is separated from the fascia by the subcutaneous (fat) layer. This is a layer of fat cells rich in nerves, blood vessels and lymphatics. Its main function is to provide thermal insulation and physical protection. To this end, it is well developed across the plantar surface, particularly across the metatarsal heads and heels where it may be up to 18 mm thick. Attached to the underlying fascia, plantar fat is divided into vertical chambers by dividing fibrous septae, which act as an effective shock absorption system. Blood supply and lymphatics
The main blood supply to the skin arises from a network (or plexus) of vessels located in the subcutaneous layer. At this lowest level, branches supply eccrine sweat glands located deep in the reticular dermis. Vessels ascend and fan out to form a second plexus in the mid-dermis. Arterioles from this level supply hair follicles and their associated structures. Other vessels ascend further to form a third plexus in the papillary dermis. From the papillary plexus, single capillaries loop upward into the dermal papillae. These tiny vessels loop and descend to drain into venules
within the papillary plexus and then descend further into the deeper dermis, eventually reconnecting with the subcutaneous blood vessels. Within the foot, the sole contains the most densely organised network of capillaries in the skin (Pasyk et al 1989), which correlates well to the thickness of the overlying epidermis. It has no thermoregulatory role. Lymph vessels are found throughout the dermis. Within the papillary dermis, highly distensible lymphatic end bulbs drain intercellular fluids and smaller particles. These empty into larger vessels, which descend to the lymphatics in the subcutaneous layer. Ryan (1995) suggests that their function is key to maintaining turgidity, which is vital to retain mechanical resilience in the skin, requiring a fine balance between supply and drainage, as dehydration and oedema can lead to a reduction in skin stiffness and deformation in the structure of collagen and elastic fibres.
Skin appendages Hair follicles and sebaceous glands. Hair follicles and their associated sebaceous glands are found on the lower limb, sparing the plantar surface. Compared with sebaceous glands in other areas of the skin (i.e. face, chest), these glands are relatively inactive. Sweat glands. Sweat glands exist in two forms. The larger apocrine glands are exclusively associated with the hair follicle in the groin and axillae, whereas the smaller eccrine gland is a simple coiled structure located in the reticular dermis with an opening directly onto the epidermis. Stimulated primarily by the sympathetic branch of the autonomic system, sweat glands are an important mechanism for thermoregulation, mainly above waist level (Ryan 1995). They are most numerous on the palms and soles. Under normal circumstances a small, steady flow of sweat is produced, which is thought to aid grip. This function is further enhanced on the palms and soles by the presence of dermatoglyphics. These skin creases, present at birth, are a result of the unique arrangement of collagen fibres in the dermis and are more prominent on
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
the weightbearing surfaces of the foot (pulp of the toes, heel and metatarsal area) and palmar area (fingerprints). Not only do they act like the tread on a tyre in conjunction with the small amounts of sweat, but within these areas, there is a dense and highly organised neural network in the underlying dermis (Montagna 1960) which provides a rich tactile perception necessary to protect the integrity of the foot.
HISTORY AND EXAMINATION OF THE SKIN Dermatological assessment consists of three parts: • history taking • clinical examination • common investigations and tests. It is often tempting when assessing the skin to leap straight to examination without resorting to the standard medical practice of history taking followed by examination. While this may give a correct diagnosis in experienced hands, often, to those new to dermatology, this will lead to an incorrect or incomplete conclusion. However, a brief initial examination may help to direct questioning for the history.
History taking Ideally, conduct the consultation in a private environment, with sufficient time to allow the patient to talk freely. You should expect to spend most of the consultation listening, only using questions to direct the history. It is important to ask patients what they think is the cause of the problem, as they are often correct. Starting the consultation by asking: 'How may I help you?' or 'Tell me about your problem' is beneficial. It lets patients know that they may talk and that there is willingness to listen, thus setting them at ease. However, certain facts are necessary to make a diagnosis and, if these are not offered, they should be asked for directly. Duration of the problem. The duration of a disease is essential to know. Whether the disease
219
is constant, deteriorating or fluctuating or whether there are periods of relapse and remission is useful. Acute or self-limiting conditions are usually inflammatory or infective (i.e. fungal infections), whereas chronic or progressive symptoms may be an indication of a more serious disease. Stressful events may give a remitting and relapsing pattern, particularly with psoriasis, eczema and lichen planus. Relieving or exacerbating factors. Does anything help the problem or make it worse? Many conditions are improved in sunlight, e.g. psoriasis, whereas others are made worse, e.g. lupus erythematosus. Relationships to physical agents. Does light, heat or cold playa part in the problem? Is it associated with any particular activity? Has injury played a part in the problem? Has there been exposure to chemical or plant material? Treatment. This is one of the most essential questions. Alongside their usual medications, often patients will have tried to treat the problem themselves and will have bought overthe-counter medications, preparations from health stores or perhaps borrowed a prescribed medication from a friend or family member. They may also have tried cosmetic preparations that they do not consider relevant. It is often helpful to ask them to bring in everything they put on the skin. In some instances the true appearance of the skin lesion may be altered or masked by previously applied medicaments. For example, a steroid cream applied to a fungal infection will dramatically increase the spread of the eruption. Past medical history. It is important to elicit any history of skin diseases, in particular psoriasis, eczema and skin cancer; all these conditions are pertinent to the lower leg and foot. Other salient conditions include information regarding a history of allergy, through either occupation or domestic exposure (e.g. epoxy resins from work or Elastoplast at home). Internal medical conditions may also be relevant, as many may manifest themselves in the skin. For example, dermatitis herpetiformis is a blistering disorder that is commonly associated with coeliac disease, a gluten intolerance affecting the gut.
220
SYSTEMS EXAMINATION
Occupation. Many occupations expose the skin to irritants and allergens. The patient may need to wear a particular garment or item of footwear as part of his job and that is causing the problem. It may be that other members of the workforce are similarly affected. Outdoor workers or workers who are exposed to wet or cold will also have problems particular to them: for instance, skin cancer is higher in those with outdoor occupations. Social history. It is useful to know who is at home with the patient as they may be able to help with the treatment. Enquiries about smoking should be made when considering circulatory problems, and alcohol consumption is relevant to a number of skin conditions, particularly psoriasis. Family history. A number of skin conditions run in families, e.g. palmoplantar keratoderma. Recessively inherited diseases may skip generations, so information is required about distant relations too.
Recognising the norm in the assessment of skin is essential. Normal variations are seen due to race and the normal ageing process. Any given population will include a significant range of skin colours. Lesions that appear red or brown on white skin, for example, often appear black or purple on pigmented skin and mild redness may be masked completely. In addition, some conditions have a distinct racial predisposition (e.g. melanoma in Caucasians). However, across all races, normal skin will not be different from surrounding skin and will feel smooth. As the skin ages, it appears more translucent with irregular pigmentation. Thinning of the skin occurs at all levels, including the subcutaneous layer, which may be evident on the plantar area of the foot. Natural turgidity and elasticity seen in younger individuals is lost. Pinching of the skin results in 'tenting', as the skin fails to return to its natural shape. As a result of decreased sweat and sebum production, the normal skin surface barrier is compromised and so is more prone to the effects of drying and irritation. A reduced immune response as the numbers of T and B lymphocytes, along with Langerhans'
cells, decrease potentially leave the skin more open to infection and malignant change. Also, any inflammation that occurs as a result of decreased immune surveillance tends to be dampened down; hence, signs of inflammation may seem less acute. With ageing, the nails may reduce their rate of growth and often become thicker and slightly yellow in colour.
Clinical examination Clinical examination of the skin uses a variety of senses. Sight is obviously the most important, but touch and smell are also valuable. Many trainees unused to dermatological assessment will shy away from touching the skin. This is clearly a natural reaction, but must be overcome in order to assess the area fully. Observation is an important stage in examination and it is important to follow a particular pattern: • general distribution (localised, widespread or regional) • individual lesion morphology • assessment of other structures • assessment of the nail • assessment of the sweat glands. General distribution
When a widespread eruption is suspected, it is important to look and ask about all of the skin. Patients may often be reluctant to discuss other areas or simply not connect them to the current condition. For example, scalp psoriasis can mimic dandruff. A patient concerned with scaly plaques on his knees may not connect the two, particularly if the dandruff has been present for some time. Many disorders have a typical pattern or predilection for specific sites, although it should be remembered that patterns could occasionally vary from the norm. Eczema has a common pattern - affecting the flexor surfaces of the arms and legs along with the face. Symmetry of the eruption should also be recorded as this usually denotes an endogenous condition. Table 9.2 highlights examples of the distribution patterns of various dermatoses.
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
221
------_._---_._---------Table 9.2
Common patterns of skin disorders
Condition
Typical distribution pattern
Atopic eczema
Antecubital and popliteal fossa, face, neck, hands
Contact dermatitis
Hands, face, feet
Psoriasis
Extensor surfaces of knees and elbows, scalp, back, nails
Lichen planus
Flexor surfaces of wrist, ankles, oral cavity, genitalia
Erythema nodosum
Anterior surfaces of shins
Individual lesion morphology
Individual lesions should be assessed. A magnifying glass is useful along with good lighting. Initially it is important, if there is more than one lesion, to describe the arrangement (Fig. 9.2). This can include: • annular (ring-like), i.e. psoriasis, lichen planus, granuloma annulare • nummular (round, coin-like), i.e. nummular eczema • discoid (disc-like), i.e. eczema, psoriasis • reticulate (net-like), i.e. livedo reticularis • arcuate (curved), i.e. contact dermatitis • grouped, i.e. insect bites, dermatitis herpetiformis
o o
0
0
0
0
... Figure 9.2
0
Note that some disorders may have a number of configurations. Koebner's phenomenon is where skin lesions of a specific disease may appear at a site of trauma which was previously unaffected. The edge of the lesion should also be inspected. Is it discrete or ill-defined? For example, psoriasis and fungal infections have much more marked, well-defined edges than eczema. Surface contour should also be noted (Fig. 9.3). Colour. To interpret the skin colour of lesions, good lighting is essential, as temperature and dependency will modify appearances. Rashes or lesions that are pink, purple or red will be due to blood. If the blood is within vessels gentle pressure will whiten or blanch the lesions - this is erythema, and can be viewed best through a glass slide or tumbler. If it is not possible to blanch the lesion, this may be due to extravasation (loss of blood constituents into the skin) or pigmentation due to melanin. Touch. It is possible to determine surface changes in texture and whether the skin disease relates only to the surface of the skin or whether it relates to the structures beneath. Light touch is required to perceive superficial changes (i.e. texture of a surface lesion), whereas progressively
Annular Flat-topped
0
0
°A~ oW· o
• Koebner's phenomenon, i.e. warts, psoriasis (Plate 10), lichen planus, molluscum contagiosum.
Nummular
~
Pedunculated
Linear
~
Dome-shaped
Grouped
~
Umbilicated
Satellite
Verrucous
•
e
o
Spire (acuminate)
Arcuate
The various configurations of lesion patterns.
Figure 9.3
The different surface contours of lesions.
222
SYSTEMS EXAMINATION
deeper pressure will reflect changes to the lower structures in the dermis and subcutaneous layers. Oedema (collection of fluid within the tissue) feels flocculent under the fingers. Typical surface changes include a soft moist texture due to excessive sweating or a dry and roughened texture due to a lack of sweating, i.e. anhidrosis. Deeper lesions may be described as hard, nodular, mobile, soft, etc. Odour. Skin odour is a neglected aspect of skin examination but is useful. Colonisations of pseudomonas, staphylococcus, or diphtheroids have distinctive smells (microbiology may help to confirm this) as do odours associated with excessive sweating (bromhidrosis) and incontinence. When examining individual lesions, clear descriptions using well-recognised terms are essential. This allows good communication between health professionals. In dermatology, there are many descriptive terms: some obvious, others less so. Familiarity with this terminology will ensure good inter-professional communication. Skin lesions can be classified as to whether they are primary or secondary. Primary lesions arise due to the initial effects of a condition; secondary lesions evolve from or as a complication of primary lesions. The distinction between primary and secondary is not always clear; some lesions can be classed as primary or secondary (Tables 9.3 and 9.4). Some of the more common terms used in assessing the surface of the skin are described below. Scaly. Normally the skin sheds skin cells individually or in small clumps. This is imperceptible to the eye. If the skin is weathered or diseased, skin shedding becomes abnormal, the clumps of skin become larger and appear as flakes or scales. These scales may be small, as in the dryness (xerosis) of atopic eczema, or large, as in ichthyosis. Scratching the surface of skin is helpful as it accentuates scaling and may help with diagnosis. Psoriasis will demonstrate pinpoint bleeding when scratched and the scaling will become more pronounced (Auspitz sign). Crusting and exudation. When the skin is injured or infected, it bleeds, oozes serum or discharges pus. This is an exudate; it dries to form a crust, which is distinguished from scale by clini-
Table 9.3
List of primary skin lesions
Term
Description and example
Erythema
Redness, often due to inflammatory response
Macule
Flat, differently coloured, e.g. freckles, vitiligo
Papule
Palpable, solid bump in skin, e.g. lichen planus
Nodule
Palpable, deeper mass than a papule, e.g. ganglion, rheumatoid nodule
Plaque
Elevated, disc-shaped area of skin over 1 cm in diameter, e.g. psoriasis
Tumour
Large mass over 2 cm in diameter, e.g. lipoma
Cyst
Subdermal, fluid-filled fibrous swelling, loosely attached to deeper structures, e.g. dermal cyst
Weal
Large oedematous bump, e.g. insect bite
Vesicle
Tiny, pinprick-sized collection of fluid, e.g. mycosis, pompholyx
Bulla
Serous fluid/blood-filled intraepidermal or dermoepidermal sac, e.g. bullous pemphigoid
Pustule
Vesicle or bulla filled with pus, e.g. acne, pustular psoriasis
Burrow
Short, linear mark in skin visible with magnifying lens, e.g. scabies
Ecchymosis
Large extravasation of blood into the tissues, i.e. bruising
Petechia
Pinhead-sized macule caused by blood seeping into skin
Telangiectasiae
Permanently dilated small cutaneous blood vessels
cal appearance and history. While avoiding hurting the patient, try to remove the crust as this often obscures the true pathology. Crusting is a common feature in eczema. Hyperkeratosis and lichenification. If keratin is abnormal, it forms thickened areas as shedding fails. These can be localised, appearing as horns on the skin and usually reflect a viral or neoplastic process. Sometimes the surface can be papillomatous (warty). The areas of thickening can be more diffuse, e.g. chronic plantar eczema or corns. Such areas are less flexible and will often crack, forming deep fissures. Lichenification is a reaction of the skin to chronic rubbing or scratch-
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
223
--------_._----------------------_._Table 9.4
List of secondary skin lesions
Term
Description and example
Scale
Flake of skin, e.g. mycosis, psoriasis
Crust
Scab, dried serous exudates, e.g. acute eczema
Excoriation
Scratch marks, e.g. pruritus
Fissure
Crack in dry or moist skin
Necrosis
Non-viable tissue
Ulcer
Loss of epidermis; may extend through the dermis to deeper tissue, e.q. venous ulcer
Scar
Fibrous tissue production post-healing
Keloid
Excessive production of fibrous tissue post-healing
Striae
Lines in skin that do not have normal skin tone, e.g. striae tensae in pregnancy, Cushing's disease
Purpura
Purplish lesions which do not blanche under pressure, e.g. vitamin C deficiency
Urticaria
'Nettle rash', e.g. drug eruption, allergy, heat
Lichenification
Patchy 'toughening' of skin, e.g. chronic eczema
Haematoma
Blood-filled blister
Sinus
Channel that allows the escape of pus or fluid from tissues
ing and involves the whole epidermis. The affected area of skin thickens and the skin markings become more pronounced. It is a common feature of atopic eczema and usually occurs on the flexures. Excoriations, erosions and ulcers. Excoriation means scratch and is usually a feature of itching or, less commonly, pain. It may represent underlying skin pathology such as scabies or eczema or indicate disease elsewhere, e.g. renal or hepatic failure. Erosions are partial-thickness breaks in the surface of the skin caused by physical injury including excoriation or where blisters have broken. An ulcer is an area of full-thickness skin loss, usually covered by exudate or crust. Atrophic. The surface of the skin is depressed and blood vessels are visible beneath. It may be due to atrophy of the epidermis or dermis. The skin is often pale and wrinkled.
Macules and patches. These are localised impalpable areas of colour change: macules are less than 1em in diameter and patches are greater than 1 cm. Papules, plaques and nodules. A papule is any lesion less than 1 em in diameter that rises above the surface of the skin. A nodule is larger than 1 em in diameter, but otherwise similar to a papule, and usually due to pathology within the dermis. A plaque is a raised lesion that is wider than it is thick and often represents epidermal pathology. Vesicles, bullae, pustules and abscesses. Small blisters less than 1 cm are called vesicles. Blisters larger than 1em are called bullae. Pus-filled vesicles or bullae are pustules, large pustules are abscesses. Weal. These are transient papular or plaquelike swellings of the skin due to dermal oedema and frequently seen in urticaria. Scars. These can be macules, papules or plaques and are a feature of repair following dermal injury. A glossary of terms can be found in Tables 9.3 and 9.4.
Assessment of other structures
When examining the skin, other structures such as the nails, hair and mucous membranes may add clues to the diagnosis. For example, lichen planus commonly causes lesions in the mouth; this may be an important finding in differentially diagnosing it from other conditions such as eczema and psoriasis. Palpation of the lymph nodes is important in patients with suspected skin malignancy. Assessment of the nail
Inspection of the nails should be included as part of the main dermatological assessment. The nail has evolved as a rigid structure to improve dexterity but in the foot the nail is purely a protective plate overlying the deeper structures and acting as a counter pressure to the volar tissues (Baran et al 1996). The nail unit (Fig. 9.4) is well provided with a rich neurovascular supply and, as a result, is sensitive to internal changes, often man-
224
SYSTEMS EXAMINATION
Dorsal nail matrix
Dorsal nail piate ---t:-:::-::::=::-:::-=-=-:::-:::-::-:=Intermediate nail plate Ventral nail plate --~"""", Hyponychium - - - j
Dermo-epidermal junction
Vertical collagen fibres in dermis PHALANX Limit of lunule
Intermediate nail matrix
Nail bed matrix Figure 9.4
Structure and anatomy of the nail.
ifesting these subtle changes in the nail structure. External factors too, such as trauma, can modify nail shape. Therefore, a proper footwear assessment should be undertaken, to complete the clinical picture, when looking for reasons for changes in nail shape, colour, etc. A glossary of the main terms used to describe nail changes can be found in Table 9.5. Key aspects of examination should include assessment of the following factors. Pattern of affected nails. It is important to always assess finger nails as well as toe nails and note any findings. Often finger nails may show changes more readily (i.e. clubbing). Where only one or two nails are affected, or one foot, local causes should be suspected, whereas nail changes in all digits in both feet and hands suggests a systemic or internal cause. On the foot, the length or the position of the toes may give clues to local nail abnormalities. Typically, the longest toe may show nail changes as a result of interaction with footwear. Rate of nail growth. There is great variation between individuals in the rate of nail growth. The average rate for a finger nail is 0.1 mm/ day (or 3 mm/month), whereas toe nails grow at a half to a third of this rate (Zaias 1980). Consequently, a normal finger nail will grow completely in about 6 months, whereas a toe nail will take 12-18 months. Such information is
Table 9.5
Glossary of nail conditions
Condition
Definition
Onychauxis
Thickening of the nail plate, usually due to trauma
Onychogryphosis
Thickened nail with a distortion in the direction of growth
Onycholysis
Separation of the nail from the nail bed, distal to proximal
Onychomadesis
Separation of the nail from the nail bed, proximal to distal
Onychocryptosis
Ingrowing toe nail
Involution
An inward curvature of the lateral or medial edges of the nail plate, towards the nail bed
Splinter haemorrhage
Longitudinal, plum-coloured linear haemorrhages (around 2 mm in length) under the nail plate
Paronychia
Inflammation of the tissues surrounding the nails
Onychomycosis
Fungal infection of the nail plate
Chromonychia
Abnormal coloration of the nail tissue
Koilonychia
Transverse and longitudinal concave nail dystrophy which gives a spoon-shaped appearance
Clubbing
Increased longitudinal curvature of the nail plate with enlargement of the pulp of the digit
Beau's lines
Transverse ridging of the nail plate seen as the result of a temporary cessation of nail growth
ASSESSMENT OFTHE SKIN AND ITS APPENDAGES 225 useful to determine the approximate time of events: e.g. the time of trauma to a nail, the likely clearance time of a haematoma. Most systemic disorders lead to a decline in the rate of nail growth but a few may have the opposite effect (psoriasis, hyperthyroidism, nail trauma and drugs). Shape of the nail plate. The breadth of the nail matrix and length of the nail bed normally dictate the shape of the nail plate (finger nails being rectangular and toe nails, quadrangular). The contour of the underlying phalanx, and toe position, may modify this. The most commonly occurring nail shape alteration in the toe nail is transverse over-curvature or involution (pincer nail). This is typically seen in the nail plate of the hallux and is often accompanied by pain when direct pressure is applied to the nail. If there is an underlying subungual exostosis (Plate 11), lifting of the distal nail plate occurs, often accompanied by pain. Frequently seen in young adults, a lateral X-ray will differentiate between this and other causes of painful nails (e.g. onychocryptosis). Internal causes of nail shape alterations include koilonychia (spooning) and clubbing: their causes are listed in Table 9.6. Colour of the nail plate and bed. Changes in nail colour (chromonychia) may arise as a result of external or internal factors. Finger nails, in particular, are vulnerable to occupational causes such as chemical agents. Colour change can occur on the surface of the nail, within the nail plate itself or below in the underlying nail bed or lunula. The use of a powerful pen torch or laser pointer shone in the pulp of the digit, through the nail plate, can help to isolate the source. Table 9.7 lists the more common causes of chromonychiao Splinter haemorrhages are plum-coloured streaks of about 3-4 mm seen running longitudinally under the nail plate. These are the result of extravasation of blood between the nail bed and plate. Typically they are caused by trauma, though, if the majority of nails are affected, disorders such as rheumatoid disease, vasculitis or skin diseases (psoriasis and eczema) should be suspected.
Table 9.6
Causes of nail spooning and clubbing
Koilonychia (spooning) Idiopathic
Clubbing Idiopathic
Hereditary
Hereditary
Iron deficiency anaemias
Lung disease: bronchiectasis lung cancers abscess lung infections fibrotic lung disease emphysema asthma in childhood
Insulin-dependent diabetes Physiologically thin nails (i.e. children) Psoriasis Alopecia Lichen planus Raynaud's disease Scleroderma/systemic sclerosis Renal transplant Thyroid disease Acromegaly Occupational (immersion in oils, acid and alkali)
Cardiovascular disease: congestive heart failure subacute bacterial endocarditis myxoid tumours congenital heart disease Alimentary disease: ulcerative colitis Crohn's disease gut cancers Endocrine: active hepatitis auto-immune thyroiditis acromegaly Other: polycythaemia cirrhosis malnutrition
Surface texture. The surface of the nail is normally smooth but changes may occur. Subtle longitudinal lines may arise with age or as a result of minor trauma, although specific diseases may accentuate their appearance (rheumatoid arthritis, peripheral vascular disease and lichen planus). Solitary lines or ridges may signify a tumour within the matrix or be the result of a previous paronychial infection. Transverse lines are common in the hallux as a result of repeated minor trauma from footwear. When transverse lines affect the majority of nails simultaneously they are known as Beau's lines and may represent a sudden period of illness. By noting their distance from the cuticle, a rough calculation can be made as to the time of the illness. Pits are small erosions in the nail found on the surface of
226
SYSTEMS EXAMINATION
Table 9.7
Causes of nail discoloration (chromonychia)
Discoloration
Cause
Nail bed
Idiopathic, subungual wart Anaemia, cirrhosis, renal disease Pseudomonas infection, blistering diseases Subungual corn, wart or exostosis, jaundice Haematoma
Brown White Green Yellow Brown/black Lunula
Congestive heart failure, alopecia Haematoma, melanoma, melanonychia
Red Brown/black Nail plate
Onychomycosis, trauma, onycholysis Nicotine or urine staining, yellow nail syndrome, jaundice Mycotic infection, onychauxis, onychogryphosis, shoes dyes, melanoma
White Yellow Brown
the nail plate. When only a few nails are affected it is considered a variant of normal but multiple nail involvement is seen in a number of skin diseases such as psoriasis, lichen planus, eczema and alopecia. Loosening or shedding of the nails. Onycholysis is the detachment of the nail from the bed in a distal to proximal fashion, whereas onychomadesis occurs in the opposite direction. The aetiology for both conditions is similar (Table 9.8) but it is most frequent as the result of trauma, particularly overzealous nail care or fungal infection. The loosened area is usually white, although in some disorders the area may adopt a different colour. Table 9.8
Causes of nail shedding
Level of separation
Cause
Onycholysis
Trauma (nail surgery, nail picking) Peripheral vascular disease Psoriasis Rheumatoid arthritis Subungual tumours Eczema
Onychomadesis
Nail matrix infection or inflammation Subungual blistering Drugs
Onychomadesis is the less common of the two conditions. Proximal detachment occurs most frequently due to acute bacterial infection of the proximal nail fold or an acute skin eruption affecting the nail bed such as a blister or psoriatic plaque. Nail thickness. Thickening of the nail (onychauxis) is probably the most commonly observed toe nail condition. Long-term trauma to the nail plate can lead to hypertrophy of the nail, often with a brown discoloration. Typically, the condition affects the hallux or longest toe as a result of footwear interaction. Other conditions such as fungal infections, psoriasis and lichen planus may also lead to onychauxis. Onychogryphosis is a more severe thickening of the nail plate often with gross deformity and a deviation in the direction of nail growth. Pachyonychia congenita is a rare inherited disorder hallmarked by congenital thickening of the nail plate. Periungual changes. The periungual tissues seal the nail unit from damage but may show disease themselves. These tissues may be breached by inappropriate nail care or prolonged immersion, e.g. water, chemicals, etc., leading to infection or chemical irritation and thus paronychia. Acute paronychia is more commonly associated with infection, whereas the chronic variety is often confined to the hands, most often as a result of irritant reactions. Other periungual conditions include tumours: • Periungual warts - usually asymptomatic, easily diagnosed by their appearance. • Corns/callus - found within the nail sulcimay lead to pain on compression of the nail plate. Nail edges may be thickened or involuted. • Subungual exostosis - diagnosed by X-ray, may lead to lifting of the nail plate. • Fibromas - associated with tuberous sclerosis. • Malignant tumours - basal cell carcinoma, squamous cell carcinoma, subungual melanoma. • Glomus tumours - causes of extreme pain when exposed to slight trauma or changes in temperature, often visible by digital illumination. Rarely are they found in the toe.
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
Assessment of the sweat glands
Table 9.9
Eccrine sweat glands are particularly numerous across the palms and soles. Normally these sweat glands play no part in thermoregulation; their activity is increased during mental stress and anxiety. When assessing sweat gland function, excessive local sweating usually has a local cause, whereas generalised sweating may have a more systemic cause. The two most common disorders are:
Cause
Causes of sweating disorders
Anhidrosis Ageing: Damage to neurological pathways
Displacement of sweat ducts Dermatological lesions
• anhidrosis - a lack of sweating • hyperhidrosis - excessive sweat production. The causes of each of these conditions are summarised in Table 9.9. When assessing sweating disorders it is pertinent to look for associated symptoms, e.g. concurrent tachycardia in the absence of a fever may suggest thyrotoxicosis. An elevated temperature and lymphadenopathy may indicate infection. Hyperhidrosis. When symmetrical, this condition is most commonly associated with young active individuals: it is usually physiological rather than pathological, with resolution occurring in the third decade. Sweat production may increase to such an extent that the skin becomes overhydrated and macerated, particularly if footwear /hosiery is occlusive. Moist fissures may develop, mostly interdigitally, along with blistering of the soles. At this stage secondary bacterial or fungal infection can occur, generating an unpleasant odour and even a brown discoloration to the skin (bromhidrosis). Anhidrosis. Anhidrosis should be considered as a condition normally associated with ageing. In severe cases cracking and fissuring of the epidermis may occur, particularly around the heel. Deep fissuring may develop into the dermis with subsequent recurrent bleeding, a common feature with eczema.
Common tests and investigations • fungal assessment and other microbiology • histological assessment • patch testing.
227
Hyperhidrosis Physiological
Examples
Sweat production decreases with age Autonomic neuropathy Diabetes mellitus Leprosy CNS disorders Eczematous or psoriatic plaques Lichen planus Miliaria Lack or loss of sweat glands Damage Iscarring to areas of skin Congenital lack of sweat glands (ectodermal dysplasia) Normal in young adults Exercise Over-clothing or occlusive footwear Emotions or stress
Endocrine disorders
Hypoglycaemia Hyperthyroidism Acromegaly
Dermatological
Associated with palmoplantar keratoderma
Other
Drugs CNS disorders Cardiovascular disorders Respiratory failure Tumours
Fungal assessment and other microbiology
Fungal diseases enjoy the conditions of the foot and are a major contributor to both primary and secondary disease. It is essential to have a high index of suspicion in any disease of the foot, particularly those that are scaly or blistering. Wood's light and mycology are the two main methods of assessment in fungal disease. Wood's light. This is filtered ultraviolet light, excluding the visible spectrum. Fungus within the skin will fluoresce under Wood's light, thus revealing subclinical infection and helping with diagnosis, but the fluorescence is not bright, so good blackout facilities are essential.
228
SYSTEMS EXAMINATION
Microsporum species are the main types detectable by this method (fluorescing green), but other pathogens also fluoresce, notably erythrasma (caused by Propionibacterium minutissimum and fluorescing coral pink). Mycology. Fungal disease usually affects the most superficial aspects of the skin and so is easy to remove for assessment by scraping. A 15 blade is ideal to do this. After carefully scraping across the skin, the scale is collected either on a glass slide or onto a small piece of black paper. Where possible, if blisters are present, the whole roof should be removed. The undersurface of the blister is then scraped to remove the fungal debris onto a glass slide; the remaining skin is sent for culture. With nails, a clipping from the most proximal part of the affected nail is useful, along with any subungual debris. Potassium hydroxide (20%) when applied to the sample on the glass slide will render the sample transparent after 20 minutes or so, thus revealing the underlying fungal elements. The scrapings are then sent for expert examination and culture, after placing the sample onto folded black card. More than sufficient scrapings should be sent whenever possible to ensure a representative result. Bacterial and viral culture. Infection with bacteria should be considered wherever inflammation or pus is present. A swab is taken by rubbing it onto the affected area; if the lesion is a blister or pustule, the surface should be broken first with a sterile needle. The swab is moistened with some of the culture medium when assessing dry lesions. Biopsy tissue can also be cultured. It is important that this does not dry out, so it is sent either in sterile water or within the culture medium of a swab. Viral specimens need a viral transport medium. Contact the microbiology lab before taking the sample, as some labs will take the specimens themselves. Histological assessment
Clinical examination of the skin only allows a view of the surface morphology, whereas histopathology is an easy and valuable adjunct whenever diagnosis is in doubt. Under local anaesthesia, small suspicious lesions are usually
excised in their entirety, whereas larger lesions need to have a carefully placed sample taken that includes both normal and abnormal skin. It is good practice to refer suspicious pigmented lesions for expert assessment rather than biopsy. The three main biopsy techniques are punch, shave and ellipse. Punch biopsies are a simple method of obtaining tissue for histology which does not require much technical skill. The punch is similar to an apple core and comes in a range of sizes from 2 mm to 7 mm diameter. The punch will penetrate the skin to a maximum depth of 7 or 8 mm and so is useful for epidermal and superficial dermal pathology. Shave biopsies are a simple method of getting biopsy specimens, effective for assessing superficial skin disease using a razor or scalpel blade. Ellipse biopsy is useful for the removal of small lesions and for larger areas. Patch testing
Allergic contact dermatitis is a common problem on the lower leg, particularly associated with footwear, medicated dressing and topical therapies. Patch testing assesses this by applying possible allergens to aluminium discs, which are placed onto the skin of the back and left in place for 48 hours. The discs are removed and the skin is assessed on the day and 2 days later. Positive reactions appear as red raised areas within the discs; sometimes the reactions can be very strong, resulting in erosions and blisters.
Recording of the assessment At the end of the skin assessment it is important to ensure accurate recording of the history and examination for a number of reasons: • to ensure good record keeping • to act as a baseline, in case of any changes in the progression of a condition • to facilitate good communication with other medical professionals. The use of colour photography and video equipment may also add objective, recorded evidence and allow the patient with poor mobility /
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
eyesight to visualise and appreciate their skin problem.
Table 9.10
HYPERKERATOTIC DISORDERS
Familial/inherited
Hyperkeratosis is the term used to describe a thickening of the stratum corneum. In the foot, the most common causes are the mechanical forces of pressure, shear and friction acting on the epidermis, leading to corns and callus formation. However, other causes include skin diseases such as psoriasis, dermatitis or fungal infections and the less common palmoplantar keratodermas (Table 9.10). Rarely, a sudden, acquired onset of symmetrical, plantar hyperkeratosis may indicate an internal malignancy.
229
Causes of hyperkeratosis
Cause
Clinical features
Palmoplantar keratoderma
Various types exist. Typically inherited forms begin in childhood
Ichthyosis
Many types. Characterised by dry, flaky skin affecting various parts of the body
Darier's disease
Palmoplantar hyperkeratosis may occur; usually lesions are punctate in form
Pachyonychia congenita
A disease characterised by thickened nails. Associated palmoplantar hyperkeratosis may occur
Acquired
Assessment of corns and callus Corns and callus are a discrete form of hyperkeratosis distinct from the secondary lesions seen with other dermatological disorders. Callus plaques (callosities) are hard, dense, yellowish plaques of hyperkeratotic tissue usually found on the plantar surface of the foot, whereas corns appear as darker, harder, invaginated areas of hyperkeratosis present either alone or within a callus plaque. Patients with calluses and/ or corns complain of a number of symptoms, ranging from cosmetic irritation to severe pain affecting gait. Symptoms include a stabbing pain when walking, which may persist when resting or subside into a dull, soft tissue ache. Callus usually is reported as a stinging, burning sensation, which is worse just after the start of rest and on resuming weightbearing. An illustrative description of callus being like 'walking on stones' may be given. An erythematous 'halo' may be evident around either lesion type. Calluses and corns appear to form in response to over-prolonged and excess mechanical stresses (such as intermittent pressure, shear and friction) from ground reaction forces on the foot and footwear during gait. Corns and callus are always found on areas exposed to mechanical stress and often in a pattern which relates to the biomechanics of foot
Palmoplantar keratoderma
Normally arises in patients from their twenties, in patterns described above
Keratoderma climactericum
Yellow/brown papules, which then coalesce to form thickened plaques across the soles of menopausal women. Fissuring is common
Reiter's disease
Red hyperkeratotic rash may occur on the soles called 'keratoderma blennorrhagica'. Difficult to distinguish from pustular psoriasis
Chronic dermatitis
Hyperkeratotic lesions may be observed accompanied by fissuring and crusting
Pustular psoriasis
Yellow/brown sterile pustules occur with a hyperkeratosis of the palms and soles, typically in older patients
Syphilis
Distinctive copper pink papules may occur on the sole with hyperkeratosis
Lymphoedema
Dirty brown lesions may occur over oedematous areas of the foot and lower leg
Hypothyroidism
A mild hyperkeratosis may occur on the soles but resolves with treatment
Tinea pedis
Hyperkeratosis may occur as part of the eruption
230
SYSTEMS EXAMINATION
function. The few surveys undertaken into the incidence of callus and corn lesions on the foot are in general accordance as to their epidemiological features (Gillet 1973, Merriman et al1986, Springett 1993, Whiting 1987). The commonest sites and lesions include (Fig. 9.5):
101-2 (2nd) 102-3 (4th) 103-4 (3rd) .... 104-5 ·••·(1st) Oiffuse callus
Apices of toes
Site of seed corns
Common site of seed corns Plantar aspect of heel
A
Plantar aspect
2nd toe 3rd toe 2nd 3rd 4th toe 0i'l:--- Subungual 2nd corn 5th toe 1st
B
Dorsum
Figure 9.5 The common sites for corns and callus formation on the feet (Merriman et al 1987).
• diffuse callus beneath the third and fourth metatarsal heads • callus solely beneath the second, first and fifth metatarsal heads • dorsal corns on the fifth toes followed by the fourth, third and second • interdigitallesions between the fourth/ fifth toes followed by first/second and third / fourth toes. Sex incidence ratio is between 1 :2 and 1 :4 male to female, with mode age of symptomatic onset between 40 and 70 years. The incidence decreases with reduced weightbearing and shoe wearing. The site of the lesion, an indication of its severity, size, texture (hard and glassy or soft), duration and stimulators/ exacerbators, e.g. a particular activity and/or pair of shoes, should be noted, along with colour differences and lesion contours, bulk, depth and width. It is assumed that the maceration which appears as a milky yellow region under a callus plaque or corn is due to excess trauma and, as a result, water is squeezed from the viable layers of the epidermis into the lower keratinised layers of the stratum corneum. The features of maceration and extravasation may be considered as clinical indicators of marked mechanical stress (Plate 12). Suitable management of these lesions is urgently required to prevent tissue breakdown and ulceration. Types of corn Seed corns. The aetiology of seed corns is not clear. The empirically proposed association with tension stress has neither been proved nor disputed. These lesions appear similar in structure and biochemically to other mechanically induced hyperkeratoses. Unpublished work using highpowered liquid chromatography (HPLC) shows that they are not plugs of cholesterol as previously thought but, in common with other hyperkeratoses, have a high cholesterol content compared with normal plantar skin (O'Halloran 1990). Seed corns tend to occur at the margins of weightbearing areas of the plantar aspect of the foot either singly or as disperse clusters.
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
Hard corns. A hard corn (Plate 13) appears as a darker patch within the epidermis, often with a callus covering. Texturally it is hard, glassy and dense when touched with a scalpel. When enucleated, a classic corn nucleus appears as a cone, although they may be any shape or multinucleate. Under greater trauma the contents of the papillary capillaries may be extruded into the epidermis as a brown-black stain (extravasation). A corn forming over a bursa may be associated with the formation of a sinus into the bursal sac; infection may result. Vascular corns. When the skin is made translucent by application of water, alcohol or oil, clinical signs below the surface of the lesion become apparent. Intrusions of vascularised dermal tissue into the epidermis can be seen in vascular corns and, if cut, this vascular tissue bleeds profusely. These lesions usually occur at sites of excess mechanical stress, may have a relatively long history and may be painful on direct pressure. These features suggest that the lesion is a vascular corn rather than a foreign body or wart. Some practitioners make a distinction between vascular and neurovascular corns; others consider that they are one and the same. Soft corns. Soft corns occur interdigitally and appear as soft, soggy epidermal masses (macerated tissue) which can easily blunt the scalpel blade. Pain is a frequent complaint. The condition appears to be caused by poorly fitting footwear, disease processes affecting the skeleton, e.g. rheumatoid arthritis, or biomechanical anomaly, e.g. excess pronation where the toe tissues are compressed and sheared in ill-fitting footwear. Fibrous corns. These arise from long-standing corns and involve the presence of fibrous tissue in the dermis below the corn. The affected tissues have an altered biomechanical behaviour: they appear more firmly attached to deeper structures than normal. Shear stresses occur at the tissue interface and, as this tissue is unable to dissipate stress as efficiently as normal tissue, there may be a perpetuation of what appears to be chronic irritation of tissues, causing further fibrosis to develop. The precise aetiology of these lesions is not clear.
231
Other causes of hyperkeratosis. Palmoplantar keratodermas (PPK) are a complex group of relatively rare disorders which are difficult to classify. Historically, such conditions were named purely on clinical and histological appearance, which has led to a confusing array of nomenclature (Ratnavel & Griffiths 1997). The consistent feature within this group of diseases is hyperkeratosis of the palms and soles. Unlike normal callus, the amount is much increased with a rapid return rate following debridement. Typically, lesions bear no correlation to any weightbearing patterns. Palmar lesions may range from one or two minor patches to complete involvement. The majority of these diseases are hereditary but spontaneous cases can arise. Clinically, PPK may be categorised into one of four distinct patterns of disease:
• diffuse PPK - diffuse hyperkeratosis across the palms and soles (usually sparing the arch) (Plate 14) • focal PPK - discrete patches of hyperkeratosis with normal skin in between • punctate PPK - numerous punctate corn-like lesions spread across the palms and soles • PPK with ectodermal dysplasia - PPK of any variety, with accompanying features of ectodermal abnormalities (e.g. hyperhidrosis, neurological or dental malformations). Many other skin diseases may lead to the development of hyperkeratosis, which often takes on a different texture from the mechanically induced type. For example, in psoriasis the skin may flake off with a scalpel and bleed due to malformation of the epidermis (Au spitz sign). Callus associated with ichthyosis tends to be thick and tough and there will be evidence of the condition on other body sites.
BLISTERING DISORDERS The term blister is used to describe any fluidfilled lesion which may occur as the principal feature of some relatively rare dermatological disease or as a feature of more commonly seen disorders (Table 9.11). Blisters can develop at a number of levels in the skin:
232
SYSTEMS EXAMINATION
Table 9.11
Main causes of blistering on the lower limb
Disorders with blistering as the principal feature
Disorders where blistering may occur as a secondary feature
Epidermolysis bullosa
Friction - most common variety seen on the feet due to pressure and shearing forces
Bullous pemphigoid Pemphigus Dermatitis herpetiformis (rare below the knee)
Fungal and bacterial infections (e.g. tinea and erysipelas) Diabetes - an uncommon complication associated with hyperglycaemia Thermal injury (e.g. burns, cryosurgery) Eczema Erythema multiforme Severe sunburn/photosensitivity
• Superficial. These blisters occur in the stratum corneum and are associated with infections, e.g. tinea pedis. Superficial blisters are more prone to rupture, leaving open erosions which may be complicated by secondary infection. • Intraepidermal. These occur in the lower layers of the epidermis, usually the stratum spinosum, and are associated with, for example, acute eczema and viral vesicles. • Subepidermal. These occur at the dermal-epidermal junction and are associated with, for example, epidermolysis bullosa. Differential diagnosis requires a thorough history and examination (including information on concurrent illness, drug therapies and family history) along with the general pattern and distribution of the disease. Family history is a key feature in epidermolysis bullosa (EB), an inherited group of disorders where the skin reacts to minor trauma by blistering; hence the feet are commonly involved. The spectrum of the disease ranges from EB simplex (minor blistering of the hands and feet with minimal scarring and little nail involvement) to a potentially lethal recessive dystrophic form (with more widespread blisters and scarring). As the disease is inherited, the onset is usually in childhood. Epidermolysis bullosa acquisita is an
acquired form, akin to EB simplex, which normally affects middle-aged patients with a similar pattern. Pemphigus is a relatively rare blistering disorder seen in middle age. Lesions tend to be intraepidermal (which rupture easily) and have an insidious onset often without a history of trauma. Unlike EB, pemphigus rarely affects the feet but oral lesions may be present. In both conditions, Nikolsky's sign may be present - the ability to raise a blister when firm finger pressure is applied across the affected skin. Bullous pemphigoid (Plate 15) is distinctive in that it usually affects the over-sixties with large tense subepidermal blisters emerging on urticated skin, including the foot. Mucous membrane involvement is not a common feature. Typically seen on the extensor surfaces but rarely below the knees is dermatitis herpetiformis. Blisters are typically small and grouped, with the appearance of herpetic lesions. Pruritus is a common early symptom. Unlike pemphigus, oral lesions are not observed, but the majority of sufferers have also coeliac disease of the jejunum.
INFLAMMATORY CONDITIONS OF THE SKIN Eczema Eczema is a descriptive term encompassing a wide variety of inflammatory diseases, many of which are pertinent to the lower limb. Clinical features vary greatly between each form of eczema and so are presented separately. Subtypes of eczema Atopic dermatitis. This increasingly common form of eczema presents at any age but is most common in childhood. Itch is the main symptom, with rash localised to the flexures. The itching and subsequent scratching can be severe. In some patients dryness and scaling is the major feature. Patients often have other allergic diseases such as hay fever or asthma. The signs are all manifestations of scratching and rubbing. First, the skin roughens and
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
reddens; with continued scratching the skin becomes broken and later infected. The usual pathogen is Staphylococcus aureus, which produces golden weeping and crusted skin. Later, the skin thickens with accentuation of the normal skin folds (lichenification), with fissures developing where the skin is less flexible. Asteatotic eczema. This is a common form of eczema usually seen in the elderly, especially those in institutional care. It results from low humidity, poor rinsing of soaps or detergents or over-vigorous washing. The usual symptom is soreness and itching, most frequently on the shins. The skin is scaly, pink and the surface broken in a crazy paving pattern. Discoid eczema. Discoid eczema is a very localised form of eczema. It presents as multiple, isolated, and coin-shaped lesions. Usually patients will complain of itching and, because of the shape of the lesions, assume they have a fungal infection. On examination, the lesions are red, scaly and superficially infected with golden crusting. Patients generally have dry skin or a previous history of eczema (Case history 9.2).
------------l Case history 9.2 Emma was a 24-year-Old student nurse and was referred for treatment of her ingrowing toe nail. She mentioned that her main symptom was itching rather than soreness. She had wondered whether it was a fungal infection. She had bought some antifungal cream and had been using it for 3 weeks. She was concerned, as the toe appeared to be worsening and her 'infection' was spreading. She was otherwise well, apart from a childhood history of hay fever and eczema. She was currently living in the hospital nursing residence. On examination, the nail appeared normal although the nail bed was inflamed in relation to a 2 cm circular patch of redness and scaling. She had a number of similar lesions on her lower legs and some appeared infected. Her skin was generally dry. Diagnosis: Diagnoses considered at that time were ringworm (fungal infection), although the culture and microscopy were negative; Bowen's disease, although Emma was really too young for this and had not had much sun exposure; and psoriasis, but she did not have a family history or other signs of psoriasis. Finally, a diagnosis of discoid eczema was made. Emma used a weak steroid and moisturiser, which cleared her symptoms quickly, and her skin returned to normal.
233
Lichen simplex. In this condition, patients usually complain of one or two itching patches. It frequently occurs on the medial aspect of the ankles and lateral calves. The itching may be very severe and keep the patient awake at night. The skin reacts to the scratching and rubbing by becoming thickened and lichenified (see above). Sometimes the lesions resemble plaques and other times nodules. The lesions are usually pink or brown and may be mistaken for lichen planus or psoriasis (see below). Stasis dermatitis (venous eczema, gravitational eczema). This form of eczema affects the lower
legs. It usually occurs in patients with venous disease (previous varicose veins or deep venous thrombosis). Patients will complain of itching or soreness and may have a history of previous venous ulceration. The skin is red, scaly and weeping, usually in association with an ulcer or area of varicosity. The underlying skin may feel firm and be discoloured blue brown with previous leakage of blood into the skin. Occasionally, the rash can spread beyond the areas of venous disease. One should always consider allergic contact dermatitis, as this is a common secondary feature. Pompholyx. This is an acute eczema of the palms and soles. It is usually associated with a number of different forms of eczema elsewhere. As the plantar skin is so thick, instead of the skin weeping when it is inflamed, it forms small blisters under the skin instead. These can occasionally be mistaken for eczema elsewhere.
Psoriasis This is a very common group of diseases. In its most usual form, it consists of well-defined, red plaques with loosely adherent silvery scale localised to the extensor surfaces. Two percent of the population is affected and may present at any age but the second and third decades are the commonest. Scaly areas develop over weeks or months in the scalp, around the sacrum and umbilicus. The flexures and genitals may be affected. The nails have characteristic changes that are a useful aid to diagnosis: they develop pitting and ridging. The nail may come away
234
SYSTEMS EXAMINATION
from the nail bed (onycholysis) and the undersurface of the nail can develop thick scaling. The damage is only transient. Arthritis is commonly associated with psoriasis and may take on a number of forms. Disease severity of the arthritis does not parallel the extent of the skin disease. Psoriasis and its variants commonly affect the lower legs. Subtypes of psoriasis Classic plaque psoriasis. This symmetrical rash affects the extensor surfaces of the skin. On the lower leg, the knees and shins are frequently involved and in this site may be thick and persistent, covering the whole shin. The plaques are variable in size, pink, red or purple and well demarcated. The scales are large and silver in colour and can be easily scraped away, revealing pinpoint bleeding. Usually nail changes will be evident on the toes. Guttate psoriasis. This acute variant follows a streptococcal sore throat. Within a couple of weeks, small innumerable plaques of psoriasis cover the body. The rash tends to resolve with no treatment in 2 to 3 months. Occasionally it can be recurrent or go on to develop into classical plaque type. Palmar plantar pustular psoriasis (Plate 16). This variant occurs primarily in middle-aged, female smokers. It is characterised by pustules on the palms and soles, with or without classical disease elsewhere. The pustules initially are creamy coloured; as they mature, they turn brown; finally, the roof falls away, leaving a scaly depression. They are commonly mistaken for fungal or bacterial disease but culture of the pustule is always sterile. A single digit may be all that is involved; in this form, the nail may be destroyed permanently. Smoking cessation does not help the rash. Generalised pustular psoriasis and erythroderma. Occasionally, psoriasis may be pustular
on the body. In this form, it is widespread, of acute onset, often with systemic upset. Lakes of pus can develop on the skin which later scale. Patients usually have a previous history of psoriasis. Occasionally, psoriasis can be so wide-
spread it affects the whole body. With this, there is loss of normal skin function (barrier against infection, heat and water loss) and patients can become very ill (death is not unknown, usually due to coexisting conditions). This is called erythroderma.
Vasculitis This condition frequently presents on the lower legs. The rash may have been precipitated by a new medication or an infection or another inflammatory medical condition. Clinically, there is inflammation within the blood vessels that results in leakage of blood into the surrounding skin. Lesions do not blanch. Early lesions are raised, red and itchy. Later, the skin may blister or ulcerate. Occasionally, the rash may be very extensive; commonly, it is modified by areas of pressure and may be accentuated around the shoe or sock line. Apart from ulceration, skin involvement is usually only a minor problem. Generalised involvement is sometimes a problem, with inflammation of vessels occurring in the gut, joints and kidneys that occasionally may result in renal failure or, rarely, death.
Lichen planus (Plate 17) Lichen planus (LP) is a common inflammatory condition that frequently affects the lower leg. The main presenting symptom is itch and rash. The itch is often very severe; patients tend to rub more than scratch, as sometimes the rash is tender. The rash may be very widespread, appearing characteristically on the wrists, shins and sometimes diffusely on the body. The mouth is often sore; the genital mucosae can be involved. Scalp involvement may lead to permanent hair loss. The nails are also involved. The clinical appearances are classical. The rash consists of multiple flat-topped, polygonal papules that have a shiny surface. The colour is pale pink through to violet and sometimes brown. Resolving lesions often leave marked persistent pigmentation. Nail involvement produces pits on the nail surface; later, the nail thins and becomes abnormal, sometimes resulting in destruction of
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
the nails. Inside the mouth, LP can appear as white lacy streaks on the mucosa to blisters to ulcers. On the lower leg, LP can become very thick (hypertrophic). LP frequently develops in areas of skin injury (koebnerisation), leading to bizarre linear forms of the rash. LP of the soles is less distinct, but the symptoms are similar and usually associated with more typical rash elsewhere. Lichen planus is usually relatively shortlived 0-2 years), but hypertrophic disease may become chronic.
Granuloma annulare Frequently misdiagnosed as tinea, this eruption is an idiopathic disorder that predominantly affects people under 30 years old (particularly children). Starting as a single red papule, it spreads concentrically (up to several centimetres in some cases), becoming concave in the centre with a pink papular edge. The lesions, which can be single or multiple, occur most commonly on the hand but also occur on the foot and shins. Unlike tinea, the lesion is rarely scaly and does not itch. Diagnosis is confirmed by biopsy. The condition may be rarely associated with diabetes mellitus. Necrobiosis lipoidica may resemble this lesion but tends to have a yellowish hue.
Necrobiosis Iipoidica (Plate 18) This condition occurs on the shin and is commonly seen in diabetics. Patients may be asymptomatic or complain of rash or ulceration. The lesions start as red patches, which enlarge, the centre becomes depressed and the skin yellows. Blood vessels may be visible traversing the patch. Occasionally, lesions ulcerate. Sometimes the rash may precede the diagnosis of diabetes or rarely may be the presenting feature. They are often multiple.
Other inflammatory conditions Sunburn. Exposure to sunlight (UVB radiation) will lead to an erythema after a latent period of 1-3 hours, depending on the amount of exposure. Excessive exposure can lead to
235
desquamation (peeling) and, in the long term, can increase the risk of malignant changes in the skin. Chilblains (perniosis). This is a familial vasospastic response to prolonged exposure to cold. Typically, lesions begin on the apices of the toes, fingers and occasionally the ears. In women, lesions may appear in the region just above the footwear line where the ankle is only covered by thin hosiery (sub malleolar perniosis). The chilblain begins as an erythema, turning into a purple, swollen lesion that may itch and burn. Ulceration of lesions is not uncommon. Erythrocyanosis. A relatively common disorder, erythrocyanosis commonly affects young, overweight women, particularly those working in a cold environment. Exposure to cold invokes a vasospastic response, resulting in a purple-red discoloration in the buttock, thigh and shin area accompanied by a burning sensation. Erythema multiforme. This skin disorder is characterised by symmetrical, concentric 'target' lesions occurring on the hands, feet and limbs. Individual lesions may have a blistered bluishred centre with a more vivid surrounding erythema. Involvement of the genital, oral and conjunctival areas is not uncommon and appears in the more severe form of the disease known as Stevens-Johnson syndrome. The causes are diverse, but 50% of cases are idiopathic: known causes include drug eruptions and viral and streptococcal infections. Differential diagnosis should include other causes of blistering and fungal infections. Negative fungal culture and the symmetry of the eruption should establish the diagnosis.
ALLERGIES AND DRUG REACTIONS Allergic contact dermatitis (Plate 19)
Typically, this condition occurs as a result of the skin becoming sensitised to a specific allergen (a type IV hypersensitivity reaction), so that subsequent exposure to the allergen produces an acute reaction of erythema, weeping and blistering at the point of contact.
236
SYSTEMS EXAMINATION ---
---------------------------------------------
The site of the reaction depends on the area of skin exposed to the allergen. Sensitisation is more rapid on thin or moist skin; hence, reactions are most commonly seen on the face and antecubital fossa. Due to its thickness, the plantar surface of the foot rarely becomes involved. Shoe line eruptions tend to be seen on the margins where the skin becomes thinner towards the dorsum. The popliteal fossa is also an area of thinner skin and, occasionally, may show reactions: e.g. to the dyes used in nylon tights. The common allergens affecting the lower limb are listed in Table 9.12. It is important to recognise that sensitised T cells may spread from the contact site and provoke eczematous type lesions elsewhere on the body. When the cause of the reaction is not apparent, patch testing should be undertaken to identify the causative agent. Differential diagnosis should be made from psoriasis and fungal infections. Depending on the point of exposure lesions may be symmetrical or asymmetrical with a well-defined edge. Fungal cultures and microscopy will typically be negative. Allergic dermatitis rarely affects children and the elderly, possibly due to a less vigilant cell-mediated immunity. With psoriasis, lesions should be present elsewhere and nail changes are likely. Juvenile plantar dermatosis
Juvenile plantar dermatosis is thought to be a variant of contact dermatitis. The condition arises in schoolchildren as a scaly, erythematous, glazed eruption, typically affecting the forefoot Table 9.12
Common causes of allergies in the lower limb
Location
Common allergen
Thigh (pocket area)
Phosphorus sesquisulphate (matches)
Popliteal fossa
Dyes in nylon tights
Foot and ankle
Venous leg ulcer treatments Chromates (leather tanning) Adhesives (epoxy resins) Metals (nickel in buckles) Medicaments, especially those containing lanolin and parabens
and plantar surfaces of the toes, sparing the interdigital areas. Fissuring may accompany the condition. Differential diagnoses include tinea infection, psoriasis, contact dermatitis and adverse drug reaction. The symmetry and glazed appearance of the condition, along with the patient's age, are usually enough to make the diagnosis. With a contact dermatitis, a positive patch test would be obtained. Drug reactions
Reactions to drugs may arise due to: • a true allergic reaction to a drug (hypersensitivity) • the effects of overdosage (toxic reaction) • side effects of a drug • alteration, by the drug, of the normal immune response. The difficulty in differentiating the above factors is that, potentially, they can all mimic virtually any skin lesion. When a drug reaction is suspected, a thorough drug history is required (including any over-the-counter preparations the patient may be using). Most often the offending drugs are the ones taken in the last 2-3 weeks, although reactions are not uncommon in drugs taken safely for many years. Withdrawal from the drug usually results in resolution of the condition within a week or two. Drug reactions affecting the lower limb are rare. Typical patterns of drug eruptions include: • toxic erythema - generalised erythema accompanied by fever • urticaria • erythema multiforme • vasculitis - typically seen as a painful purpura on the shins • erythema nodosum.
INFECTIONS OF THE SKIN The surface of the skin is an effective barrier against most environmental agents, but through injury to the skin surface or when exposed to virulent organisms this barrier fails. The pattern of
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
disease is very much dependent on the type of infection and so will be considered accordingly.
Viral Verrucae. Verrucae (Plate 20) are the predominant viral infection on the foot caused by infection of the skin with human papilloma virus (HPV). Around 5% of 16 year olds will have warts at anyone time (Williams et al 1991). The virus affects the stratum spinosum and causes hyperplasia and formation of a benign tumour. Typically, the plantar wart is found under a point of high pressure, e.g. the metatarsal heads or a bony prominence (Glover 1990). In its early stages it appears as a small, dark, translucent puncture mark in the skin. More mature lesions show thrombosed capillaries, a 'cauliflowerrough' surface and are painful when pinched. The patient may complain of increased discomfort on starting to walk after a period of rest, e.g. first thing in the morning. Different types of HPV cause different wart lesions, e.g. flat, genital or plantar. Verrucae protrude above the level of the skin unless they occur on weightbearing surfaces. When they are found on weightbearing surfaces they protrude into the skin and, as a result, are more painful. Mosaic warts are made up of multiple, small, tightly packed individual warts and may not be painful, whereas plantar warts may be single or multiple and are usually painful. Occasionally, periungual warts may develop around the nail edge and lead to distortion of the nail plate. Verrucae can usually be diagnosed from their clinical appearance; however, they can be confused with corns (particularly neurovascular or fibrous) and foreign bodies. Verrucae can occur on non-weightbearing and/or weightbearing areas of the foot, unlike corns and most foreign body injuries, which tend to occur solely on weightbearing areas. There may be multiple verrucae present, not only on the feet but also on the hands, the pinching of which tends to cause a sharp pain, whereas corns and foreign bodies give rise to pain on direct pressure. Verrucae appear encapsulated and the skin striae are
237
broken; corns do not appear encapsulated and the skin striae are not broken but pushed to one side. Any wart with an atypical appearance, particularly in the elderly or immunosuppressed, should be biopsied as, rarely, the lesion may undergo malignant change. Molluscum contagiosum. This is a contagious infection (usually of children) which usually involves the trunk but can affect the leg and foot. Infection with the causative poxvirus, usually by close contact, leads to a papular lesion, which may range in size from a pinhead to a pea. The hard, shiny pedunculated lesion has a central crater from which cheesy material may be expressed by pinching it. The uniqueness of this lesion makes the diagnosis straightforward. Herpes zoster (shingles). Shingles is a recrudescence of previous chicken pox, usually along a single dermatome. It can occur at any age, but most frequently in the elderly or immunosuppressed. It presents as a 1-3-day history of pain or burning in one limb followed by haemorrhagic blisters and later superficial ulcers. Pain may persist for many weeks and months. Herpes simplex. Herpes simplex (cold sores) rarely affect the lower leg, although they may involve the thigh in rugby players (serum pox) following infected oral exposure to an eroded area of skin on the sports field.
Bacterial Bacterial superinfection, which is very common particularly in the various forms of eczema, was discussed earlier. Primary bacterial infections are less common (Plate 21). In all these conditions, full assessment by bacterial swabs is essential. Ecthyma. This infection affects the full thickness of the epidermis. The main pathogens are Staphylococcus aureus and Streptococcus pyogenes. The patient may have recently been to a humid climate or had an insect bite. It presents as a shallow ulcer with a thick, crusted top. Cellulitis. Cellulitis or erysipelas is a serious infection usually of the lower leg caused most commonly by Streptococcus pyogenes. It presents as a flu-like illness that is rapidly followed by a painful red advancing area, usually on the lower
238
SYSTEMS EXAMINATION
leg. The affected area becomes swollen and the skin discoloured. The skin may even blister, necrose and ulcerate. Commonly, a 'portal of entry' is found such as tinea pedis (see below) or a fissured patch of eczema. Pitted keratolysis (Plate 22). Bacterial overgrowths on the sole of the foot secrete proteolytic enzymes that produce multiple pits within the epidermis. The pathogens are microaerophilic diphtheroids. This is particularly common in patients with sweaty feet or who wear trainers. Usually it is asymptomatic, but sometimes the skin thins sufficiently to be tender. Odour is commonly offensive in such patients. Erythrasma. This bacterial infection of creases and flexures occurs between the toes of the foot. It is commonly mistaken for tinea pedis. The pathogen is Propionobacierium minutiesimum, The skin is usually macerated and red/brown in colour. Again, it has a strong odour and fluoresces coral pink in Wood's light.
Fungal There are four patterns of fungal infection of the foot (tinea pedis). Asymmetry is a feature common to all subtypes. In all situations, scrapings are essential to fully assess for fungal disease. Interdigital scaling is the commonest form, usually presenting as itching and fissuring. This usually occurs between the third to the fifth toes where the skin is most macerated. The rash initially begins on one foot, only later extending to the other toes, nails and other foot. A variety of fungi and yeasts are implicated. Extension onto the dorsa of the foot (Plate 23). In chronic disease, the fungus can spread onto the dorsa of the foot, producing itchy scaly rings with an active edge. Fungal culture will help differentiate this from discoid eczema. Typical fungal causes include Trichophyton rubrum and less commonly Epidermophyton floccosum. Blistering in the instep. The inflammatory reaction on the sole to fungus tends to produce blistering (Trichophyton mentagrophytes). It is usually unilateral. Removal of the blister roof will allow closer inspection and it may be sent for culture.
Moccasin foot. The soles of the foot can be generally involved with fungus (Trichophyton rubrum), producing thickened scaly feet. Often the disease affects both feet. The nails may also be involved. Most patients are unaware of the problem but will have a previous history of infection. Onychomycosis. Tinea pedis may progress to the toe nails (onychomycosis), typically as a result of repeated trauma (e.g. from footwear). Infection may occur superficially on the nail plate or subungually invading under the hyponychium. Proximal subungual involvement occurs rarely in immunocompromised patients or following chronic paronychia. Total nail involvement and dystrophy may result. Tinea incognito. Misdiagnosis of fungal infection is a problem as often the incorrect diagnosis made is eczema. The use of topical steroids to reduce inflammation consequently allows the unsuspected fungus to grow unchecked by the immune system. Patients present with a history of a persistent rash, usually on the foot, which fails to respond to steroid creams. The potency of the steroid used is often very high. The rash is red, ill-defined with nodules within, that when squeezed express pus. Scrapings confirm the presence of fungus (Case history 9.3).
INFESTATIONS AND INSECT BITES Scabies. The mite Sarcoptes scabiei causes scabies. Itching is often severe despite sometimes having minimal evidence of infestation. Patients may describe itchy nodules or blisters. They will usually have family members presenting at the same time with itch. The signs are generally that of eczema but blisters and excoriations are more pronounced. The primary lesion is the burrow of the mite. It appears as a linear or serpiginous white line with scaly opening at one end and a minute grey or red dot at the other end (the mite). The mite may be extracted with a needle and examined using a microscope. Scabies should be suspected in any patient with a pronounced itch, and other sites of involvement (hands and trunk) should be sought.
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
Case history 9.3 Philip was a 25-year-old footballer who presented with a 4-year history of a troublesome right great toe nail. He was concerned, as the nail was discoloured and growing abnormally. A brief examination of the toe nail suggested fungal disease. Philip explained that since playing professionally he commonly developed a blackened nail on his right foot but recently the colour of the nail had changed and become crumbly. He also mentioned that from time to time he had athlete's foot but had never sought treatment for this. Initially, when asked what medication he was on, he said none; then he remembered that he had been using some steroid cream. A friend had given him some that he used rather unsuccessfully, to treat a patch of eczema on the same foot. On closer questioning, it seemed that the cream had initially helped the eczema but each time he stopped the treatment the eczema just came back again. On examination, the nail was grossly thickened with creamy linear discoloration at the medial margin extending to the proximal nail fold. The ridged nail was detaching itself from the nail bed. The fourth and fifth interdigital spaces on both feet showed scaling and blistering. Examining the right ankle revealed a thickened erythematous scaly plaque within which were inflamed nodules. The area was markedly excoriated. Microscopy of scrapings from the web space and eczematous plaque revealed the presence of fungus. Culture of the toe nail clippings grew the same fungus, Trichophyton rubrum (a common fungus affecting the foot). Diagnosis: Fungal nail and web space disease with tinea incognito of the ankle. The whole problem cleared after discontinuing the topical steroid and a 3-month course of antifungal tablets (terbinafine). He was also advised to check the fitting of his soccer boot.
Insect bites. A variety of insects will bite the skin, producing itch or painful nodules or blisters on the skin. The lower leg is commonly involved as it is often exposed (biting insects and fleas). Clues to suggest insect bite are grouped lesions, often along a sock or shoe line, and a history of presence of domestic animals or proximity to farms. Larvae migrans. A variety of hookworms that are gut parasites in animals may find themselves in humans. Cats and dogs are the main carriers. The immature form of the parasite penetrates the skin and the larvae migrate under the skin to produce loops and tortuous tracks.
239
Patients usually complain of itch and blistering, usually contracting the disease on beaches abroad but occasionally in the UK. The pattern of migration makes diagnosis easy. Fortunately, the disease is self-limiting.
DISORDERS OF THE SUBCUTANEOUS TISSUE The subcutaneous layer is a layer of primarily adipose (fat) tissue and covers most of the lower limb, particularly the thighs, anterior shins and plantar surface. Atrophy. Atrophy is the most common disorder affecting the subcutaneous layer. It occurs most frequently as a result of ageing and trauma (e.g. heel pad atrophy in long-distance runners and the elderly) or as a result of granulomatous change (panniculitis) around injection sites (typically, diabetic patients using insulin injections). Affected skin becomes depressed and scarring may occur. Painful piezogenic papules. On the plantar surface, around the heels, herniations of fat from the heel pad into the dermis may be evident on standing. As solitary or multiple nodules they may occasionally give rise to heel pain (Shelley & Rawnsley 1968), usually in middle-aged females. Diagnosis is established, as pain will result from direct pressure while standing, but when nonbearing the lesion completely disappears. Erythema nodosum. This is an uncommon eruption affecting the shins presenting as painful nodules on the shins and less commonly the thighs and forearms. The rash starts as painful areas that enlarge into hot, red nodules, which are acutely tender. These then resolve over a matter of weeks. The redness fades and takes on a bruised appearance. The condition is important, as it is often associated with other diseases such as sarcoidosis and a variety of infections.
SYSTEMIC DISORDERS AND THE SKIN The skin is an easily accessible structure and may often give clues regarding internal disease.
240
SYSTEMS EXAMINATION
Typical disorders which may affect the skin include connective tissue and endocrine diseases. Common systemic disorders and their effects on skin are summarised in Table 9.13.
PIGMENTED LESIONS Pigmented lesions represent a large part of general dermatological practice; this is also the case on the lower legs. Pigmented lesions arise as a result of a variety of processes, both neoplastic and inflammatory. Close attention to the clinical history and signs will allow distinction between most lesions. Freckles or ephelis. These are probably the most common pigmented lesions seen on the skin. They are most common in those with fair skin who have been exposed to sunshine. Lesions are usually innumerable; they are visible but not palpable and the pigmentation within is usually evenly distributed and is generally slight. Darker
freckles can also occur, particularly after prolonged or excessive sun exposure. Lentigo. A lentigo is a lesion where there is an increase in the number of melanocytes within the skin, resulting in a pigmented patch. Lesions usually occur in older patients and usually arise on sun-exposed sites. Again, the lesion is visible and not palpable; it tends to be solitary and the pigmentation within it is usually light and always even. Seborrhoeic warts. These are particularly common, developing with advancing age. They appear as well-defined, rough, warty, slightly raised lesions that have a stuck-on appearance. They usually occur on the trunk and proximal limbs but can arise on the lower leg. They do not develop on the sole. They are always benign but can become inflamed after minor trauma and may be mistaken for malignancy. Pigmented naevi. Moles are collections of pigmented naevus cells (melanocytes) in the skin
Table 9.13 Systemic conditions and their associated skin changes Condition
Associated skin changes in the lower limb and foot
Diabetes mellitus
Increased incidence of skin infections (fungal and bacterial), skin stiffening, ulceration (neurovascular), diabetic bullae, necrobiosis lipoidica, granuloma annulare
Lupus erythematosus
Erythematous scaly plaques with follicular plugging
Systemic lupus erythematosus
Periungual erythema, splinter haemorrhages, onycholysis and leuconychia. On the legs, erythromelalgia and erythema nodosum
Dermatomyositis
Periungual erythema with characteristic 'ragged cuticles'. Occasional calcification within the skin
Systemic sclerosis/scleroderma
Tight waxy skin with later distal digital atrophy with calcinosis, ulceration and occasionally gangrene
Ehlers-Danlos syndrome
Fragile skin with frequent bruising, hypermobility, poor wound healing, typically showing large scars upon the knees
Rheumatoid arthritis
Skin atrophy, nodules, vasculitis with periungual infarcts, splinter haemorrhages and onycholysis with longitudinal ridging of the nails
Hyperthyroidism
Hyperhidrosis, clubbing, onycholysis, hyperpigmentation, pretibial myxoedema
Hypothyroidism
Anhidrosis, leuconychia, pruritus, palmar and plantar hyperkeratosis
Acromegaly
Hyperhidrosis, skin thickening, coarse hair
Hepatic disease
Clubbing, spider naevi and pruritus
Renal disease
Hyperpigmentation or skin yellowing, nail changes - half-and-half nails, onycholysis
Reiter's syndrome
Keratoderma blennorrhagica
Internal malignancy
Hyperpigmentation, palmoplantar keratoderma, secondary skin tumours, pruritus, nail clubbing, bullous eruptions
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
that contain the pigment melanin. The nature of moles will vary enormously depending on how many naevus cells are present, where in the skin they occupy and how pigmented they are: obviously, the greater number of naevus cells there are, the larger and more protuberant the lesion. Lesions that are close to the epidermal surface tend to be red/brown in colour; however, the further down the pigment is in the skin the bluer the colour becomes. In addition, the intensity of the colour will depend upon how much pigment is being produced. Moles are sometimes present at birth; their number increases during life, most commonly in the first two decades but can develop at any age. Moles may become larger and more pigmented with age and occasionally may regress. The clinical appearances of moles are infinitely variable, therefore making classification on macroscopic grounds alone almost impossible; however, they can be defined according to their microscopic appearances and knowledge of these patterns may be useful in the clinical setting. Junctional naevi. Collections of melanocytes along the dermal-epidermal junction, junctional naevi are the usual type of mole for the sole of the foot. In this site the pigmentation usually follows the ridges and troughs on the epidermal markings. They are usually impalpable, the colour is red brown, and is symmetrical. They commonly occur in children and generally 'mature' by melanocytes falling away into the dermis, forming intradermal naevi. Here, the melanocytes have all fallen into the superficial dermis. Often, the naevus cells stop producing pigment and plump up. Clinically, the lesions are therefore protuberant and pale or skin-coloured. They may continue growing in adulthood. Compound naevi have both junctional and intradermal components and therefore share clinical features of both types of lesions. Blue naevi. Melanocytes that have never reached the epidermis and instead have proliferated in the deeper dermis have a blue appearance. These often develop in later life, especially on sun-exposed sites, especially the dorsa of hands and feet and on the scalp. Blue naevi are small (less than 5 mm) and may be slightly
241
raised. They can be differentiated from vascular malformations in that they do not blanch. They are almost always benign. Malignant melanoma (Plate 24). In the assessment of pigmented lesions the potential diagnosis of melanoma should always be considered. There are a number of clinical symptoms and signs that should alert you to the diagnosis (Table 9.14). Itching is an early and significant symptom that should be sought. Often, it may be the only presenting symptom, particularly where the melanoma is not in general view. There may be a change in the surface of the mole, skin creases may be lost, and hair follicles and pores may disappear. Almost always there will be an increase in the size, shape or thickness of the mole. This occurs over weeks and months and usually is asymmetrical. Colour will change within a mole; pigment can both increase and decrease within the same lesion. Also, as the melanocytes invade deeper into the skin, they may appear blue or even black. Rarely, melanoma may lose all pigmentation, making diagnosis very difficult clinically (although the patient may recall a pre-existing pigmented lesion). Bleeding, the surface of a melanoma may ulcerate, particularly in advanced disease. The tumour may have spread by the time it is picked up; this may be clinically evident with tumours developing along the lines of lymphatic drainage (in transit metastasis), in the draining lymph nodes or at distant sites (for instance presenting as fits, weight loss or shortness of breath). Melanoma is very rare before puberty and usually occurs in large congenital moles. The
Table 9.14 Suspicious signs and symptoms in a pigmented lesion
Symptoms
Signs
Change in sensation Change in size Change in colour Change in shape Change in outline New lesion
Loss of skin markings Irregular margins lrreqular pigmentation Bleeding Ulceration
242
SYSTEMS EXAMINATION
majority of melanomas develop in later life, occurring in fair individuals on sun-exposed sites and most commonly in women on the lower legs. Melanoma may arise on the sun-protected sole of the foot and, as it is hidden from view, it usually presents late. Any unusual lesion on the foot should be suspected, particularly if there is pigmentation (Case history 9.4).
SKIN TUMOURS Tumours of the skin need careful assessment, as there will be clues in both history and examination that will lead to accurate diagnosis. Most lesions will be benign, but a small proportion will be malignant (Table 9.15) and therefore life threatening. Early referral of such lesions to a dermatologist can improve prognosis enormously. Points that should be sought in the history are, obviously, site of the lesion, how quickly it is growing, whether there are associated symptoms such as irritation or pain, or whether there are similar lesions elsewhere. Clinical signs that should be recorded are size, shape, surface, colour, outline, temperature and consistency. Dimensions should be recorded in the notes, and where possible the lesion should be photographed.
Case history 9.4 Amiddle-aged female patient presented for assessment of her softcorns, which had been troublesome for many years.After taking a history, the feet were examined, revealing trivial disease; however, on her posterior left calfthere was a suspicious pigmented lesion. On questioning the patient, she remembered having a mole on her leg for a number of years but apart from occasional minor irritation itcaused her no concern. She tended to burn when she was inthe sun and had spent the first 20 years of her life living in Florida. She did not have anyfamily history of melanoma. She was otherwise well. On examination the lesion was 1.5 em in diameter, the pigmentation was varied and the outline irregular. Within the lesion there was a nodule which had become ulcerated. She was referred to a dermatologist, who confirmed the suspected diagnosis of melanoma by an excision biopsy. She remains free from recurrence.
Table 9.15
Principal tumours affecting the lower limb
Benign
Malignant
Dermatofibroma Seborrhoeic wart Haemangioma Lipoma Clear cell acanthoma Pyogenic granuloma Eccrine poroma Glomus tumour
Bowen's disease Basal cell carcinoma Squamous cell carcinoma Melanoma Kaposi's sarcoma Porocarcinoma Metastasis
Benign tumours Dermatofibroma. The lesions are very common, particularly on the lower leg. They are usually symptomless; often the patient is unaware that the lesion is even there. Sometimes they catch when the leg is scratched or shaved. They are felt as firm tethered nodules within the skin, sometimes with a slightly elevated surface. They often have a pigmented halo and for this reason may be mistaken for more sinister lesions. They are always benign. Pyogenic granulomas (Plate 25). These are common vascular proliferations that grow rapidly over a few days or weeks. They usually follow a minor injury. The surface is very easily broken and bleeding may be prolonged and frequent. In time, the lesion develops a surface epithelium that is more resilient, ultimately resembling a haemangioma. Eccrine poroma. These are benign tumours of the sweat duct that arise on the palms and soles, typically in the over-40 age group. They are pink or red, painless and usually 1-2 em in diameter with a moist surface, surrounded by a moat-like depression. Occasionally, they can undergo malignant change.
Malignant lesions Bowen's disease. Bowen's disease is squamous cell carcinoma confined to the epidermis only. It is a condition of the elderly, usually pre-
ASSESSMENT OF THE SKIN AND ITS APPENDAGES
senting as a well-defined, erythematous, scaly patch on the lower leg. When the scale is picked off the surface may bleed and weep. It occurs most commonly in women (suggesting a sunrelated aetiology). The lesions are sometimes multiple. Left untreated they may persist for many years; however, sometimes this disease can progress on to true invasive squamous cell carcinoma. Basal cell carcinoma. Basal cell carcinoma usually presents on the face but occasionally it occurs on the lower legs. Usually it presents as a fleshy nodule with a pearlescent appearance, having small blood vessels grossing the surface. Advanced lesions ulcerate and if neglected may become very large. Despite being locally destructive they do not metastasise. Occasionally, they remain superficial and indistinguishable from Bowen's disease. Squamous cell carcinoma. Squamous cell carcinoma (See) is a common malignant tumour of the lower leg presenting as a lump or as a bleeding ulcer. The tumour grows over a period of weeks and months. In time the tumour becomes painful, particularly if it is invading bone or nerves. Usually it will develop on a background of sun damage but it is also associated with exposure to arsenic and aromatic hydrocarbons. Occasionally, it may develop with an old scar or leg ulcer; this should be considered, especially in ulcers that fail to heal with conventional measures or ulcers with fleshy or rolled edges. Metastasis generally tends to be a late event, usually to the regional lymph nodes. An see that arises on the foot may invade deeply with only minimal surface involvement, mimicking pressure or neuropathic ulcers. Often, in this site the tumour will have multiple sinuses that discharge offensive-smelling material. Kaposi's sarcoma. This rare vascular tumour was described originally on the lower leg in males of eastern European extraction. It presents as blue-black or purple patches that later become plaques and nodules. Tumours range in diameter from 1 to 3 cm; they are usually multiple. Later lesions may involute or ulcerate. Oedema may become a problem. Kaposi's sarcoma is associ-
243
ated with human herpesvirus 8 and immunosuppression, notably HIV (Lebbe 1998). Porocarcinoma. This rare sweat duct tumour often occurs on the lower leg. The history and clinical appearances are similar to see but the tumours are more likely to recur and metastasise. Metastasis (Plate 26). Tumours of the lung, prostate, thyroid, kidneys and breast rarely spread to the skin. Usually when they do, it tends to be the scalp and upper body. However, tumours arising on the lower legs can metastasise to the draining lymph vessels and nodes, particularly melanoma and Sec. The tumours will usually appear as subcutaneous nodules; they may be large. They may be firm and may feel as if they are attached to related structures. The patient will usually have a history of previous tumours, but occasionally the metastasis may be the presenting feature.
SUMMARY There is no point assessing a patient's skin unless the information is to be used to benefit the patient. A diagnosis is formulated from all the data gathered from the assessment and the practitioner's knowledge and clinical experience. Epidemiological data - information such as age and gender - may help. Information from observation, clinical tests and special investigations will also help to reduce the list of possible conditions. In most instances the diagnosis will become obvious, but on occasions it may not be possible to reach a definitive diagnosis. In this case a provisional diagnosis has to be made and the cycle of the disease process must be awaited for further enlightenment. Where a diagnosis is not available, the practitioner may decide to treat the symptoms. Occasionally, the effect of a treatment can be a diagnostic aid in itself; e.g. a vesicular eruption that resolves with the use of an antifungal implies that the aetiology was mycotic. When a condition is diagnosed, the practitioner must decide what action is necessary based on available evidence.
244
SYSTEMS EXAMINATION
REFERENCES Baran R, Dawber R P R, Tosti A, Haneke E 1996 A text atlas of nail disorders. Martin Dunitz, London Cork M 1997 The importance of the skin barrier function. Journal of Dermatological Treatment 8: S7-S13 Forslind B 1994 A new look at the skin barrier. A biophysical and mechanical model for barrier function. Journal of Applied Cosmetology 12: 63-72 Fortune D G, Main C J, O'Sullivan T M, Griffiths C E M 1997 Quality of life in patients with psoriasis: the contribution of clinical variables and psoriasis-specific stress. British Journal of Dermatology 137(5): 755-760 Freinkel R, Traczyck T 1985 Lipid compositions and acid hydrolase content of lamellar granules of the foetal rat epidermis. Journal of Investigative Dermatology 80: 441-448 Gawkrodger D J 1992 An illustrated colour text of dermatology. Churchill Livingstone, London Gillet du P 1973 Dorsal digital corns. Chiropodist July Glover M G 1990 Plantar warts. Foot and Ankle 11(3): 172-178 Harlow D, Poyner T, Findlay A, Dykes P 1998 High impairment of quality of life in adults with skin diseases in primary care. British Journal of Dermatology 139 (SuppI51): 15 Lawton S 2000 A quality of life for patients with skin disease. Skin Care Campaign Directory, London Lebbe C 1998 Human herpesvirus 8 as the infectious cause of Kaposi sarcoma: evidence and involvement of cofactors. Archives of Dermatology 134(6): 736-738 McKee P H 1996 Pathology of the skin with clinical correlations. Mosby-Wolfe, London Merriman L, Griffiths C, Tollafield D 1986 Plantar lesion patterns. Chiropodist 42: 145-148 Montagna W (ed) 1960 Advances in the biology of the skin: cutaneous innervation. Pergamon Press, Oxford Norlund J 1994 The pigmentary system: an expanded
perspective. Annals of Dermatology 6(2): 109-123 Office of Population Census and Surveys 1991-1992 Morbidity statistics from general practice. Fourth National Study 54: 22 O'Halloran N 1990 A biochemical investigation into the cholesterol content of seed corns. BSc dissertation, University of Brighton Pasyk K A, Thomas S V, Hassett C A, Cherry G W, Faller R 1989 Regional differences in the capillary density of the normal human dermis. Journal of Plastic and Reconstructive Surgery 83(6): 939-945 Ratnavel R C, Griffiths WAD 1997 The inherited palmoplantar keratodermas. British Journal of Dermatology 137: 485-490 Ryan T J 1995 Exchange and the mechanical properties of the skin: oncotic and hydrostatic forces control by blood supply and lymphatic drainage. Wound Repair and Regeneration 3: 258-264 Shelley W B, Rawnsley H M 1968 Painful feet due to herniation of fat. Journal of the American Medical Association 205: 308 Springett K P 1993 The influence of forces generated during gait on the clinical appearance and physical properties of skin callus. PhD thesis, University of Brighton Venning V 2000 The dermo-epidermal junction: an important structure in dermatology. Dermatology in Practice 8(1): 6-8 Whiting M F 1987 Survey of patients of large employer in SE England and Dept of Podiatry, University of Brighton. Unpublished, protected data Williams H C, Potter A, Strachan D 1991 The descriptive epidemiology of warts in school children. British Journal of Dermatology 128: 504-511 Zaias N 1980 The nail in health and disease. SP Medical, New York
FURTHER READING Baran R, Dawber R P R, Tosti A, Haneke E 1996 A text atlas of nail disorders. Martin Dunitz, London Dawber R P R, Bristow I R, Turner W A 2000 A text atlas of podiatric dermatology. Martin Dunitz, London Goldsmith LA 1991 Physiology, biochemistry and molecular biology of the skin. Oxford University Press, Oxford Harman R, Mathews CAN 1974 Painful piezogenic pedal papules. British Journal of Dermatology 90: 573
Lewis-Jones S 2000 The psychological impact of skin disease. Nursing Times 96(27): 2-4 (suppl) Leung A K C, Chan P Y H, Choi M C K 1999 Hyperhidrosis. International Journal of Dermatology 38: 561-567 Litt J Z, Pawlak G P 1997 Drug eruption reference manual. Parthenon Publishing, London Windsor A 2000 Sampling techniques. Nursing Times 96(27): 12-13 (suppl)
CHAPTER CONTENTS
Introduction 245 Why assess footwear?
246
The 'anatomy' of the shoe 246 The 'anatomy' of sports shoes 248
Footwear assessment L. Merriman *
Shoe construction 248 Lasts 248 Measurement 249 Methods of construction 250 Materials used in construction 252 Allergy to shoe components 253 Style 253 Suitable shoe styles 253 Unsuitable styles of footwear
255
Assessment of footwear 255 History taking 256 Assessment of shoe fit 256 Wear marks 261 Suitability 264 Everyday shoes 264 Hosiery 264 Summary
265
INTRODUCTION Assessment of footwear and hosiery is important as many foot health problems are associated with the foot coverings. The majority of women experience foot pain associated with wearing shoes (Frey 1995, Frey et al 1992). Footwear assessment may also be used for forensic purposes (McCourt 2000). Additionally, examination of the footwear can confirm a diagnosis or occasionally suggest a pathology which might not otherwise have been considered. Effective footwear assessment depends upon the ability to differentiate a suitable from an unsuitable shoe. To do this it is necessary to understand the function of the different parts of a shoe and the properties of the materials used in their construction. This chapter therefore begins with a section about footwear before the methods of assessment are described in detail. Well-fitting shoes are an essential part of the treatment of foot problems and the ability to assess fit is therefore an important tool. Several methods of measuring fit are described, together with some simple observations. The ability to read the pattern of wear on a shoe is a skill that can be used to assess how the foot functions within the shoe. Some of the common patterns are described. It is hoped that this chapter will stimulate the reader to observe footwear and understand its significance. "Linda Merriman wishes to acknowledge the work of Janet Hughes. This chapter is largely based on her work in the previous edition.
246
SYSTEMS EXAMINATION
Why assess footwear? Assessment of footwear is essential in the investigation of foot problems for many reasons. Perhaps the most important of these is that shoes give valuable information about how the foot functions during gait. It complements the assessment of the locomotor system (Ch, 8), much of which relies on barefoot observations, by assessing the way the foot functions during daily activity, i.e. wearing shoes. Examination of the wear and crease marks of footwear can be an aid to diagnosis as well as helping to complete the global picture. Another reason for the importance of footwear assessment is that unsuitable footwear can affect the efficacy of treatment or help to prolong a condition which might be alleviated by suitable shoes. In some instances shoes are the cause of the problem and effective treatment will consist simply of suggesting alternative shoes. Footwear is often neglected by practitioners and its assessment has not always been given the attention it deserves. This type of assessment is more of an art than a science and relies heavily on the experience of the observer. Gaining this experience is complicated by the enormous range of footwear that is available and the many different methods of construction. Observations of shod and unshod populations in the literature demonstrate that the unshod populations have fewer foot deformities than those who wear shoes. Research has also shown that when members of an unshod population start to wear shoes the incidence of foot problems increases. There is no experimental evidence showing that footwear is the cause but it is clearly implicated. Simple observation reveals that some feet survive even the most unsuitable footwear. The feet that survive unscathed are probably those with good bone structure and foot function. However, it can be assumed that for some feet inappropriate shoes will certainly cause deformity. Patients with foot deformity often report similar symptoms in relatives but note that they were not present as children. The shoes most likely to cause problems are those which do not fit well or are in some way
unsuitable. Well-fitting, suitable shoes should always be encouraged. While the basic function of footwear is protection both from hard and rough surfaces and from the cold, the appearance is often more important to the wearer. Patients exhibit strong resistance to change where their footwear is concerned. Many patients, particularly female, choose to ignore advice regarding sensible footwear, believing that what they consider to be an elegant appearance is more important than foot comfort. It is the authors' experience that patients are more receptive to footwear advice if the reasons for changing from highheeled court shoes to lace-ups can be explained. They are also more likely to believe that their shoes are too small when this is demonstrated by a few simple tests. It is important, however, not to be too dogmatic regarding patients' shoes. Advice is more likely to be accepted if it is made clear that smart shoes can still be worn for special occasions.
THE 'ANATOMY' OF THE SHOE Figure IO.IA shows the parts that make up an average lace-up shoe. The components can be grouped into those that make up the upper and those which form the sole. They are described individually below. Additionally there are areas which need reinforcement. These are highlighted in Figure IO.IB and described under the area they reinforce. Vamp. The upper is made of two main sections which are together moulded into the shape of the top of the shoe. The front section, which covers the forefoot and toes, is called the vamp. In some shoes the vamp is made of more than one piece, creating a decorative pattern; however, seams other than those joining the main sections are not recommended as they limit stretch ability and may rub bony prominences. The vamp is usually reinforced anteriorly by the toe puff, which maintains the shape of this section and protects the toes. In safety shoes this area is reinforced with steel to protect the toes from crushing injury. This reinforcement can be the cause of toe problems if it does not fit well.
FOOTWEAR ASSESSMENT
A
Insole
247
B
Tongue Topline
Eyelets --,...--,...--f--~/ (Oxford lacing) Throat line
-+---,ll---
Stiffener
Quarter
Heel --Toppiece
,/n_-
----,1-----''''
-#1'--- Vamp
