Disorders of the lower leg 57 CHAPTER CONTENTS Paediatricians’ estimates of the frequency of this diagnosis 1 2 Bone disorders 745 vary from 4% to 20% of all children. During recent decades, several hypotheses have been put forward but none gives a Lesions of the plantiflexors 745 good explanation for the symptoms. As it occurs between the Pain . 745 ages of 6 and 12, which is not the period of maximum rate of Weakness . 752 growth, ‘growing’ cannot be the real reason for the pain. What- ever the origin of the pain, it disappears spontaneously and Short plantiflexor muscles . 753 completely after the age of 12 years.3,4 Lesions of the dorsiflexors 754 Pain . 754 Weakness . 756 Lesions of the plantiflexors Lesions of the invertors 756 While the patient rises on tiptoe, still the best test of integrity Pain . 756 of the plantiflexor mechanism, the examiner notes if there is Weakness . 758 any pain or weakness. Lesions of the evertors 758 Pain . 758 Pain Weakness . 760 Disorders causing neurological weakness of Tennis leg the foot 760 This is the common term to describe a tear in the triceps. It occurs most often in the medial belly of the gastrocnemius muscle, usually some 5 cm above the musculotendinous Bone disorders junction.5 The disorder was first described by Hood in 1884.6 For As this book covers ‘non-osseous’ lesions of the moving parts decades it has been regarded as a ruptured plantaris tendon,7,8 of the body, little attention will be paid to bone disorders. For but careful clinical examination of patients suffering from this differential diagnostic reasons, however, it is as well to bear in disorder shows this to be false.9 mind that, if the patient complains of continuous localized The history is quite simple. During a vigorous contraction pain, without special clinical findings during functional exami- – for example, when starting to sprint, pushing a car or lifting nation, the possibility of a bone disorder should be considered a heavy weight – the patient experienced sudden severe and a radiograph or a bone scan obtained. Paget’s disease, pain in the calf. From then on, the patient was unable to dors- metastases, primary bony tumours and osteomyelitis are iflex the foot during walking and needed to tiptoe on the possibilities. affected side. Children between the ages of 6 and 11 years who complain Examination reveals pain during resisted plantiflexion but of diffuse pain in the legs but have a normal clinical examina- no weakness. In the supine-lying position, dorsiflexion at the tion are very often regarded as suffering from ‘growing pains’. ankle is found to be markedly limited when the knee is in the © Copyright 2013 Elsevier, Ltd. All rights reserved. The Lower Leg, Ankle and Foot extended position but becomes normal when the knee is Posterior compartment syndrome flexed. This implicates the gastrocnemius muscle, part of The patient, usually a young man, reports an ache and swelling which is in spasm around the tear. The difference in range in the calf some hours after unaccustomed exercise. Walking between a flexed and an extended knee in a disorder of the is uncomfortable and increases the swelling. Examination gastrocnemius muscle is another example of the constant- shows that rising on tiptoe is not difficult and not really uncom- length phenomenon. Palpation of the calf reveals the tender fortable. The calf is diffusely swollen and the skin is red and area in the medial gastrocnemius, with either swelling and warm to the touch. Passive dorsiflexion of the foot is severely haematoma if the lesion is recent, or induration around the limited by loss of elasticity of the calf muscles. Palpation tear if it is old. After a severe rupture, it is possible to palpate reveals uniform tenderness of the whole calf muscle without the gap in the medial gastrocnemius. Ultrasonography is the any localized tender area.20 The symptoms result from muscle imaging technique of choice to demonstrate size and grade of ischaemia, produced by increased tissue fluid pressure in the the lesion.10,11 closed fascial compartment. The difference from tennis leg lies in the discrepancy between marked restriction of passive dor- Differential diagnosis siflexion and almost painless tiptoe rising. Treatment is surgical Although the diagnosis is obvious, it is as well to bear in mind division of the deep fascia. some other possibilities. Referred pain to the calf High rupture of the Achilles tendon This is most frequently the consequence of compression of the Although the similar onset and localization of the pain can S1 nerve root, whether by a primary posterolateral protrusion cause diagnostic confusion, this condition should hardly be of nuclear substance at the fifth lumbar level in a younger a problem if a proper clinical examination is done. Weak patient, or by a compression in a narrowed lateral recess in an resisted plantiflexion and no spasm during passive dorsiflexion older person. When these conditions are suspected, a careful in a ruptured Achilles tendon contrast with the findings in history must be taken and a clinical examination of the lumbar tennis leg.12,13 If there is any doubt, a simple test can be done spine must be performed. Positive findings during lumbar as follows.14 The patient lies prone, the foot hanging over examination, together with painless tiptoe rising, confirms the the edge of the couch. The examiner squeezes the calf diagnosis. muscles. If the Achilles tendon is intact, the foot moves into plantar flexion. When there is total rupture, no movement Treatment results. Different types of treatment have been advocated for tennis Deep venous thrombosis in the calf muscles leg. Most authorities advise partial or total immobilization for Differential diagnosis from this condition is very important. small tears21 and surgical suture for serious ruptures.22,23 Instances have been described of patients with tennis leg In our opinion, surgery for this condition is scarcely ever 15 receiving anticoagulants, which aggravated their condition. necessary and partial or total immobilization by plaster cast or The main historical difference is in the onset. In deep venous strapping is obsolete. When such treatment is instituted, the thrombosis, pain appears after immobilization or after sitting formation of a chronic adherent scar is promoted, which results 16 for a couple of hours, and not during vigorous contraction of in disability lasting several months. The aim of treatment in the calf muscles. Clinical examination does not show limited muscle tears is to allow the torn fibres to heal in such a way passive dorsiflexion, although passive dorsiflexion and resisted that mobile and functional scar tissue is formed. If normal plantiflexion can be painful. The calf muscle and leg are swollen enlargement of the muscle is impaired by adhesions, self- and the foot becomes oedematous because of obstruction to perpetuating inflammation will be the result. Muscle belly venous return. Palpation of the tender spot shows other dif- lesions (tennis leg is an excellent example) therefore need a ferences: in thrombosis the whole calf muscle is painful to the different and more functional approach. The aim must be to touch and sometimes a painful ‘string’ can be palpated deep restore normal movement in the damaged muscle as quickly 17,18 within it. as possible. This can be achieved with combined treatment: Rupture of a Baker’s cyst early compression to decrease the amount of haemorrhage; In long-standing rheumatoid arthritis of the knee, chronic aspiration and infiltration with local anaesthetic as soon as the distension with fluid can weaken the posterior ligaments patient is seen; and deep transverse friction and electrically and during exertion these can rupture. Sudden pain in stimulated or active contractions of the muscle during the next the knee, followed by swelling of the leg and oedema few days.24 During the recovery period, the muscle must be of the ankle, strongly suggests venous thrombosis.19 Here, protected by a raised heel pad, which enables the patient to the long-standing rheumatoid arthritis and the absence of use the unaffected parts of the gastrocnemius without strain injury suggest the diagnosis, which can be confirmed by on the line of healing. arthrography. Technique: infiltration Intermittent claudication As soon as the patient is seen – whether on the day of the The history is characteristic: pain in one calf is brought on by accident or some weeks or months later – local anaesthesia is walking and relieved by rest. Routine clinical examination induced at the site of the partial rupture. The patient lies reveals nothing. Diminished or absent pulsations at the dorsalis prone, the knee slightly bent and the foot plantiflexed, to allow artery of the foot and posterior tibial artery may be found. maximal relaxation of the muscle. The tender spot is located Angiography confirms the diagnosis. and gripped between thumb and index finger (Fig. 57.1). If 746 Disorders of the lower leg C H A P T E R 5 7 Fig 57.1 • Infiltration with local anaesthesia in tennis leg. Fig 57.2 • Deep friction to the gastrocnemius muscle. there is any fluctuation, an attempt is made to aspirate the where the same movement starts again. The procedure is con- haematoma. Once that has been done, 30–50 mL of procaine tinued for about 15 minutes. During friction, the fingers do 0.5% is injected using the usual infiltration techniques. As the not move in relation to the skin – fingers and skin move as a spot is never precisely localized (gentle pressure does not unit over the muscle fibres. reveal tenderness in the deeper part of the muscle, whereas At first, massage is given gently. After 5–10 minutes, friction strong pressure is apt to hurt throughout the belly) and the can be deeper and firmer but must always remain gastrocnemius muscle is a large structure, up to 50 mL of a comfortable.