Limb problems

Chapter 6 Limb problems



Ming Kon Yii, Marinis Pirpiris



6.1 Introduction


Diseases of the arterial, venous, lymphatic, neurological and musculoskeletal systems of the limbs produce specific symptoms requiring special examination techniques for each system. These techniques are discussed in more detail under the clinical problems that arise from diseases of the bones, joints, vessels, nerves and other structures of the upper and lower limbs. It is essential to compare both sides during examination. In all patients it should be routine to test the urine for diabetes, a common aetiological factor in diseases affecting the lower limb.



Arterial circulation




Examination



1 Inspection


In patients presenting with claudication, the limb may appear normal. The onset of rest pain indicates that a more severe disease has developed and that gangrene is imminent. The most notable feature of the severely ischaemic limb is its colour. Dusky cyanotic rubor is common, most marked on standing. Hence on first appearance the foot may appear to be well vascularised with rubor. Rubor slowly fades to an unhealthy pallor when the patient lies down and the cutaneous veins are empty, appearing as pale blue gutters in the skin. Trophic skin changes include epithelial thinning and hair loss (hair loss alone is often just age related). Ulceration or gangrene may be seen over pressure points such as: the malleoli; beneath the heads of the metatarsal bones and under the heels; on the dorsum of the foot (a common site of minor trauma); or at the tips of the toes and fingers.


Buerger’s test is performed with the patient supine. In patients with rest pain and pregangrene, cadaveric pallor and guttering of surface veins develop upon elevation of the legs to 45° and exercise of the foot, indicating lack of adequate arterial vis a tergo. This is followed by dependent rubor as the legs are lowered over the side of the bed when the patient sits up. The skin of the foot and toes rapidly becomes reddened, slowly changing to dusky cyanosis. During dependency the maximally dilated small vessels of the ischaemic limb are insensitive to normal vasoconstrictor stimuli and respond passively to changes in transmural pressure. Dependency, with its attendant pressure increase, causes passive hyperaemia. It is thus important to exclude patients who present with a red foot because of severe ischaemia.



2 Palpation


The leg with arterial ischaemia is cool, a sign that is emphasised by comparison with the other side. Skin temperature is best appreciated by palpation using the sensitive thin skin over the dorsum of the middle phalanges (Fig 6.1). Diminished capillary return is present if more than two seconds is taken for colour to return after finger pressure is applied to the big toe.



The peripheral pulses in the affected limb are diminished or absent. The dorsalis pedis artery runs from a point midway between the malleoli to the space between the first and second metatarsal bones and is just lateral to the extensor hallucis longus on the forefoot. The dorsalis pedis may be absent in 5–10% of the population and its place may be taken by a branch of the peroneal artery. The pulse will then be felt more laterally. The posterior tibial artery is found in the soft tissue groove below and behind the medial malleolus, halfway between it and the Achilles tendon. The popliteal pulse is the most difficult to find and is best palpated in the lower popliteal fossa with the knee passively flexed. Beware that an easily felt popliteal pulse is often a sign of a pathologically enlarged popliteal artery. The femoral pulse is usually easily palpable in the groin at the midinguinal point (Fig 6.2). The effects of exercise on the appearance of the limb and on distal pulses should be assessed. In moderately severe disease, palpable pulses may disappear on exercise. It is also important to remember the surface landmarks for the various pulses in situations of ‘extremis’ when pulses may be very weak. The abdominal aorta and iliac vessels should also be examined.





Venous circulation




Examination




2 Palpation


Palpation of the lower limb confirms the presence of oedema, which initially pits on pressure. Pitting is best demonstrated by applying pressure over the subcutaneous surface of the tibia. Valvular incompetence may be detected by feeling a cough impulse at the saphenofemoral junction and by finding palpable defects in the deep fascia at the site of perforating and communicating veins along the tributaries of the long saphenous vein. The main sites of perforators are: at the saphenofemoral junction and the lower thigh medially; and in the lower leg 5 cm above the medial malleolus (often beneath a venous ulcer), and at the mid-calf and 15 cm above the medial malleolus (two fingerbreadths, a handbreadth and a handspan above the malleolus). The long saphenous vein often runs one fingerbreadth posterior to the subcutaneous surface of the tibia. Tourniquet tests can also be used to locate the site of valvular incompetence. In the supine patient the tourniquet is applied at different levels in the leg after emptying the superficial veins. If the veins above the tourniquet fill on standing when those below remain collapsed then the site of incompetence of the communications between the deep and superficial veins is above the tourniquet. If the veins below the tourniquet fill on standing then the incompetent site is below the tourniquet. In the Trendelenburg test a tourniquet or finger pressure is applied just below or over the saphenofemoral junction. Saphenofemoral incompetence is present and the test is positive if continued pressure prevents retrograde filling of the saphenous vein on standing up from the supine position and if retrograde filling with a waterfall effect rapidly occurs from above on release of pressure.



Neurological system


This system is discussed in more detail in Chapter 5. The following is a brief summary relevant to limb examination.




Examination


The aim on examination is to detect the site of a neurological lesion by evaluating disordered function. Neurological examination of the limbs commences with inspection and proceeds to assessment of motor nerve function, sensory nerve function and reflex functions. Assessment of gait and of other coordinated movements is an important component of the examination.







Musculoskeletal locomotor system




Examination


Each musculoskeletal segment, that is, the site of the presenting problem (e.g. shoulder pain) is examined fully (as described in that section) before moving on to complete the examination, which always follows the sequence: look, feel, measure, move. It is summarised below.




2 Palpation


There is a temptation to commence this part of the process by poking the painful area — something best avoided until closer to the end of the examination. Signs of heat, tenderness, swelling or oedema are noted by a hand laid gently onto the affected limb segment. Any localised swelling is noted and its physical characteristics recorded. In the supine patient, one leg may appear to be shorter than the other (apparent shortening — measured from the malleolus to a fixed point on the trunk such as the umbilicus). True shortening of the limb is established by comparing the distance on both sides from the tip of the medial malleolus to a fixed point on the bony pelvis — the anterior superior iliac spine. Accurate measurement of true shortening requires that the joints of both limbs be in an identical position, with the pelvis square to the sagittal plane and both iliac spines at right angles to the line of the spine (Fig 6.3). A fixed abduction or adduction deformity of one limb can cause apparent lengthening or shortening of that side — true shortening is checked after placing the opposite limb in a similar position of abduction or adduction. True shortening is often due to hip disease. The level can be simply and rapidly demonstrated by the disparity in span shown on bilateral palpation of the hip joint — placing the thumb on the anterior superior iliac spine and the middle finger on the greater trochanter and measuring by eye any disparity in distance between these digits on each side.





6.2 Bony lumps


The usual causes of bony lumps are injuries, benign or malignant neoplasms and malformation and inflammatory lesions (Fig 6.4). A history of injury suggests reparative bony callus as a cause. It must be remembered that fractures may occur through a pathological focal lesion and sometimes normal bones fracture with no history of injury. Primary bone neoplasms are much less common than are secondary tumours but are more common as a cause of a painfully enlarging mass in the bone. Secondaries in the bone more often present with pain alone or as a spontaneous or pathological fracture. Infections, soft tissue sarcoma and benign developmental skeletal abnormalities can also present as a painful bony swelling. Bony swellings near a joint can be mistaken for an inflammatory monoarticular arthritis. In some instances it may be difficult to tell whether a limb swelling is arising from the bone or from adjacent soft tissues. Normally, when a soft tissue swelling arises primarily from bone, it involves all layers and radiates more or less symmetrically from the bone outwards. The adjacent joints are usually normal.



The most common causes of localised bony swelling in patients aged under 25 years are fracture, callus formation, acute osteomyelitis and osteosarcoma; aged from 25 to 50 years, giant cell tumour, fibrosarcoma and chondrosarcoma; aged over 50 years, metastatic bone disease, localised myeloma and fibrosarcoma (Table 6.1). Nearly all benign tumours occur in the young and stop growing when growth is completed, so diagnosis of these is easy to make in most cases. Large tumours are not necessarily malignant, although recent increase in size does suggest the possibility of malignant change. The main features that suggest malignancy are pain, warmth and tenderness with cortical destruction on X-ray and calcification that extends into the soft tissues. The most common benign tumours are exostoses (bony hard lesions fixed to the bone found near the lower end of the femur and upper end of the tibia), osteomas (flat bony swellings frequently found on the forehead) and chondromas. Chondromas may grow in or out from the surface of the bone. Enchondroma within the bone may present as a fusiform swelling of the bone. Biopsy is essential when malignancy is suggested clinically and histological confirmation of malignancy is essential prior to radical surgery.


Table 6.1 Common causes of localised swelling of bone















Age group (years) Lesion
<25 Fracture, callus formation, acute osteomyelitis, osteosarcoma
25–50 Giant cell tumour, fibrosarcoma, chrondrosarcoma
>50 Metastatic bone disease, myeloma, fibrosarcoma



History, physical examination and radiology




2 Acute osteomyelitis


Most cases of acute osteomyelitis occur during or before adolescence. The presentation is typical of an acute inflammatory condition — in adults it is often in the setting of immunosuppression. The precise anatomical site of the lesion may be difficult to determine, but on examination a hot, tender, oedematous swelling is usually found at the end of a long bone, particularly about the knee. The organisms usually lodge in the metaphysis of the bone. There is associated systemic toxicity. The differential diagnosis is from cellulitis of soft tissue, an acute inflammatory noninfective joint lesion and, if the condition is less acute in its onset, osteosarcoma. Diagnosis is more difficult if the patient presents during the chronic phase of the disease.


The causative organism is usually one of the Gram-positive cocci such as Staphylococcus aureus or Streptococcus pyogenes. Haemophilus is becoming less common with recent advances in immunisation. Gram-negative organisms such as Escherichia coli and Pseudomonas aeruginosa must also be considered at the extremes of age, the immunosuppressed and when clinical response to treatment is not as expected. A subacute or chronic abscess (Brodie’s abscess) usually also involves the end of a long bone and manifests as a mildly tender, palpable bony thickening. As well as osteogenic sarcoma, tuberculosis must also be excluded.


X-rays show a central area of rarefaction, surrounding sclerosis of bone and deposition of subperiosteal new bone. Within about two weeks of the onset of acute osteomyelitis, an area of sclerotic dead bone (sequestrum) will appear in the central area of rarefaction (Fig 6.5). However, X-rays may not show any abnormal features in the first few days of the disease process.




3 Osteosarcoma


Most cases of osteosarcoma (osteogenic sarcoma) occur before the age of 25 years. Occasionally osteosarcoma occurs in the aged patient as a complication of Paget’s disease of bone. Osteosarcomas may also arise in bone that has been irradiated for other reasons. A painful bony lump is the predominant symptom. The onset is usually gradual, with a progressive increase in pain, a variable degree of swelling, local heat, venous engorgement and tenderness. Most sarcomas develop in the medullary cavity near the metaphysis of a major long bone; half lie in the region of the knee. A history of previous trauma may be given, that is, either incidental to the underlying process or has precipitated a pathological fracture. Palpation usually reveals a swelling close to the knee without detectable joint disease and with free joint movement.


The tumour felt is frequently much larger than the changes in bone demonstrable on X-ray. The interpretation of the X-ray can be difficult as the findings are variable depending upon the amount of osteolysis or osteosclerosis within the tumour. There is a loss of the normal bone trabecular pattern in the area of concern, combined with destruction of the cortical wall and elevation of the periosteum and extension into the surrounding soft tissues. A radiographic sign termed a Codman’s triangle is often associated with this tumour. It is a triangular area of subperiosteal new bone formation near the cortical margin of the tumour. Bony spicules are laid down perpendicular to the normal surface and may produce a sun-ray or ‘sunburst’ appearance. There is often a large soft tissue component, which is evident on the imaging. In some instances there may be little or no bony reaction, only irregular lysis of the cortex of the bone. The histological picture can also be indefinite and experienced assessment is essential. It may be difficult to make a diagnosis from an inflammatory cause, even with histology.







8 Less common causes


Hydatid disease is an unusual cause of bone swelling that is almost impossible to treat successfully and may eventually require amputation.


Myeloma. The outstanding symptom is bone pain at multiple sites, without swelling. Occasionally myeloma will present as a lump in the bone. Focal lesions are seen on X-ray as circumscribed punched-out areas of rarefaction with minimal local sclerosis; only occasionally is there cortical expansion.


Osteomas occur in children and adolescents as longstanding, small, exquisitely tender tumours mainly affecting the femur and upper tibia. The pain sometimes precedes the appearance of radiographic changes. Nocturnal pain and pain relieved by salicylates are prominent and characteristic symptoms. On X-ray the lesion is densely sclerotic with a radiolucent centre. Treatment is by surgical removal. More recently advances in image-guided radiofrequency ablation have provided a less invasive means of effecting a cure.


Enchondromas may be solitary or multiple (Ollier’s disease). Presenting complaints include tender swellings of the bones of the hands and feet. They are rarely painful unless there has been a pathological fracture. They have been reported in most bones. On X-ray there may be multiple, mottled, translucent lesions with cortical expansion but not erosion. Treatment is by curettage often combined with bone grafting. Lesions in flat bones may be locally invasive in their behaviour.


Reticulum cell (Ewing’s) sarcoma presents as a painful, tender swelling of the shaft of a long bone in young adults or adolescents. However, it is prudent to remember that in approximately 20% of cases the lesion is found in the innominate bone. It is rarely found in individuals aged under five or over 30 years old. Later these lesions are associated with systemic toxicity. X-ray shows the characteristic ‘onion peel’ appearance of subperiosteal lamination in the mid-long bone. A soft tissue mass over the area involved indicates soft tissue involvement. In the past the outcomes of treatment were disappointing with low medium-term survival rates. However, the advent and advances in chemotherapy have improved the outlook. Treatment is usually radiotherapy and chemotherapy.


Chondromyxoid fibroma occurs in young adults, mainly in the metaphysis of long bones. The X-ray findings are not characteristic and treatment is by curettage after biopsy confirmation of the diagnosis.


Tuberculosis of the bone has an insidiously mild onset, with the development of painful bony swelling. Mild systemic toxicity and joint involvement are common, in contrast to tumours of bone. As tissue necrosis and caseation are common, abscess formation with spontaneous external drainage can lead to chronic sinus formation. If the joint is involved the synovium becomes thick and oedematous giving rise to an effusion. The pannus slowly destroys the articular cartilage with active bone erosion often also occurring at the edges of the joint leading to the characteristic, yet seldom seen, radiographic appearance of periarticular osteopenia. Diagnosis depends upon isolation of acid-fast bacilli from biopsy specimens. This often requires protracted culture in specific culture media. When the lesion is limited to the metaphysis of bone, it appears as single or multilocular cysts surrounded by sclerotic bone. Initial treatment is conservative, using antituberculous antibiotics.



Diagnostic and treatment plans


A benign tumour remains localised and on X-ray has a well-defined edge. In contrast, a malignant tumour has the potential to metastasise, growth is rapid and its edge is often ill defined. The features that suggest malignancy on X-ray are cortical destruction and calcification extending into the soft tissues (Fig 6.6).



One of the main management problems is to establish the diagnosis of osteosarcoma and to exclude the differential diagnoses of subacute osteomyelitis or a benign neoplasm. It may also be difficult to distinguish neoplasia from the various cystic diseases of bone. Biopsy and histology generally provide the definitive diagnosis but must be correlated with the other clinical and radiological findings. If the diagnosis remains in doubt, conservative treatment may be started, with careful clinical and radiological observation for a period of time before radical surgery is recommended. With a definitive diagnosis of osteosarcoma surgery combined with chemotherapy improves survival. Limb salvage surgery combined with adjuvant chemotherapy, in the right setting, may provide results that are at least comparable to those with amputation and adjuvant chemotherapy. The chemotherapy is most often administered preoperatively, with the pathologist being able to examine the specimen postoperatively and comment on a better outcome should there be a higher degree of necrosis (preferably greater than 95%). Other malignant tumours may also often require limb ablation surgery.


Local excision is preferred to curettage for giant cell tumours of bone and lessens the likelihood of recurrence. There may be a temporary filling of the cavity with synthetic substances, such as bone cement, in order to observe the behaviour of the tumour in the postoperative phase, prior to definitive bone grafting.


With acute osteomyelitis, if the correct antibiotics are given early, drainage may not be necessary. In uncomplicated osteomyelitis, shorter periods of antibiotic treatment (three days of intravenous antibiotics followed by three weeks of oral antibiotics) have now demonstrated great promise. In complicated cases, a subperiosteal abscess may be suggested by the presence of local pain and oedema but if toxicity and local tenderness persist for more than 24 hours of adequate antibiotic treatment, drainage of pus is indicated. An ultrasound may often confirm the diagnosis of this condition, as may MRI of the relevant area. Whether the bone should be drilled to drain the medulla of pus in early and focal osteomyelitis is controversial. In the setting of significant disease that may compromise the bone’s vascular supply through a pressure effect, a bony window with debidement and curretage is often performed. A cold bone scan in this case may indicate necrotic bone rather than excluding acute osteomyelitis.


Chronic osteomyelitis is more insidious in onset and presents a challenge to one’s diagnostic acumen in the assessment of painful bony swellings. In areas with difficult access to medical care, it is not an uncommon outcome in open fractures. The bone is often hard and sclerotic with an area of new bone formation (involucrum) surrounding the infected site. The site may also contain necrotic bony fragments (sequestra). Purulent material may intermittently drain to the skin surface via a sinus (cloaca). Depending on the geographical location, tuberculous osteomyelitis should be considered in the list of potential underlying aetiologies. A Brodie’s abscess is a sterile fluid-containing cavity. This lesion may result from prolonged use of antibiotics for the treatment of osteomyelitis, where drainage early in the course of the illness might have been the more appropriate approach.



6.3 Musculotendinous lumps


Swellings related to muscles or tendons frequently pose diagnostic problems. They present as deep subcutaneous lumps that are within, derived from or attached to muscles. They occur in children and adults from sporting injuries; in older patients they are often due to degenerative wear and tear. The contractile capacity of muscles gives certain classic signs to lumps near them and associated with them. Lumps due to injuries, tears and ruptures are induced or thrown into greater focus by muscle contraction; the bunching of torn muscle fibres gives a focal lump adjacent to a defect. The history of injury may be obvious or occult. The entire muscle should be examined, from origin to insertion, for accurate diagnosis.


Muscle rupture and degeneration often occur at the junction of the muscle with its tendon or aponeurosis. Sometimes the injury occurs within a tendon widely distant from the parent muscle and presents as a focal lump in the tendon or a spontaneous rupture of the tendon. Symptoms and signs will then be mainly concerned with the tendon; disabilities and deformities induced by active contraction will again be diagnostic.


Benign and malignant neoplasms within and near muscles have their physical characteristics distorted by this proximity — important signs are limited mobility or fixation of the lump when the muscle is tensed and contracted. As well as becoming less mobile, swellings may change in shape and size on muscle contraction. The lump may disappear or become more difficult to feel, suggesting that the lump is within the muscle (Fig 6.7). On the other hand, the lump may occasionally become prominent only when adjacent muscles contract, suggesting extrusion from between muscle bundles or through a defect in the fascial envelope of the muscle. The patient can be asked to contract the muscle isometrically or isotonically to elicit these points or the muscle can be put on the stretch by the examiner, separating origin and insertion by passive joint movements.



It is essential to always compare the lesion with the normal side of the body and to examine the muscle concerned and its adjacent joints and tendons, both at rest and in the contracted state.




Tendinous swellings




Clinical features, diagnostic and treatment plans



Muscle swellings



1 Muscle rupture

Muscle rupture in youthful and adult patients is often due to sporting injuries. Spontaneous rupture of certain skeletal muscles, tendons and aponeurosis is also common after trivial or unnoticed strain. Degenerative wear and tear with age makes elder patients especially liable to spontaneous rupture during sport. Muscle rupture presents as a lump of bunched-up fibres that is emphasised by contraction.


Sometimes, with deeper muscles not accessible to palpation or with spontaneous tendon rupture distant from the muscle, patients present with muscle weakness or disability or a limp rather than with a lump. Biceps brachii (long head), Achilles tendon, supraspinatus (rotator cuff) and quadriceps femoris are common muscles involved. Affected characteristics of visible muscles are a tender hollow defect and deformity of the muscle at rest, with an indistinct edge adjacent to the lump. On contraction, the lump moves with the muscle and is made more prominent. Weakness and pain are present when muscle power is tested.


Ruptured long head of biceps brachii tendon. The patient is usually over 50 years; however, the injury may also occur in an athlete performing a large amount of weight training such as bench-press activities. Rupture in the older age group is usually secondary to degenerative weakness and the long head, with its complex intracapsular course over the humeral head, is particularly at risk. The patient may have felt something snap while lifting or flexing the elbow but may not have noted a precipitating event. The clinical picture is unmistakable (Fig 6.8). The belly of the muscle is distorted, looks lower than the other side, does not tighten properly on contraction and is round or semicircular in shape rather than fusiform and ovoid. Shoulder and elbow movements are free and painless — apart from evidence of degenerative joint disease or, occasionally, rheumatoid arthritis. In the younger athlete, sometimes pain may be reproduced by passive stretching of the biceps (Speed’s test) or resisted active contraction (Yergason’s test). While active treatment in either case is rarely required, there is an increasing tendency to repair proximal ruptures in the younger, high-performance athlete. Occasionally the biceps are avulsed from their distal (radial) insertion — this is usually a more acute and painful injury from lifting heavy weights and the muscle belly retracts to a higher position and sometimes requires repair to the bicipital tuberosity in order to preserve full motor power in the younger person.



Ruptured Achilles tendon. This injury is common in middle-aged squash players. It classically occurs in athletes in their 30s and 40s. The sufferer feels acute pain in the lower calf or ankle and may fall to the ground thinking he has been struck by a squash racquet. The examination findings are almost diagnostic. There is a tender defect palpable in the muscle just above the insertion of the tendo achilles into the calcaneum, with a painful tender lump above it. Active flexion of the ankle is painful and limited. The patient should not be able to stand on his toes and the foot should be able to be passively hyperextended; however, the latter signs are seldom elicited due to pain. Local bruising is not uncommon.


Complete rupture is best treated by operative repair. This is associated with 27% lower re-rupture rate compared with non-operative means. Incomplete rupture or rupture in the older patient may be treated conservatively. In this case healing with elongation is not uncommon, giving signs of a firm ovoid lump in the tendo achilles, hyperextension of the foot and weakness of plantar flexion. However, it does avoid an 11% risk of complications such as infection and adhesions between the tendon and the skin.


Supraspinatus (rotator cuff) rupture. This can accompany shoulder injuries such as dislocation or lifting strains. A degenerative rotator cuff in patients over 45 years is more prone to rupture. Active abduction of the shoulder is impaired or not possible, despite an actively contracting deltoid. The shoulder hunches laterally on attempts by the patient to initiate abduction. If the arm is passively elevated through the painful arc, it can be maintained above the head by action of deltoid and the remaining muscles (see Ch 6.4). The treatment of this pathology should include treatment of the tendinopathy and treatment of the associated bony abnormalities. The lateral edge of the acromion may impinge on the rotator cuff during active abduction of the shoulder. Surgical repair of complete rupture is the standard in young patients. In older patients a corticosteroid injection into the subacromial space combined with an exercise program to strengthen the rotator cuff and the periscapular muscles may be all that is required. Surgery in older patients is mainly for the pain-relief associated with alleviating impingement rather than gains in muscle power.


Quadriceps femoris. Rupture classically occurs just above the patella at the junction of the vastus intermedius with its tendon, due to resisted extension strain. This usually occurs in older patients but may occasionally occur in weightlifters during their deeper squats. There is a tender defect and lump at this site — knee extension is weakened but not usually absent. Surgical repair is indicated for major ruptures.


Sternomastoid ‘tumour’. Tearing of sternomastoid muscle fibres can occur in infants, causing a sternomastoid muscle ‘tumour’ with muscle spasm and torticollis (wry neck). The wry neck is seldom visible at birth. Usually within a week or two the parents notice a lump at the lower end of the sternomastoid muscle with the head being held asymmetrically and persistently rotated to one side. As the child spends more time on the one side the face and occiput become more flattened on that side. Treatment is predominantly conservative, with gentle stretching exercises supervised by a paediatric physiotherapist. It is prudent to ask for an orthopaedic opinion in order to exclude congenital cervical vertebral anomalies. The syndrome can also occur in older children and adults. In older children inflammatory conditions of surrounding soft tissue structures, optical disorders and rotatory subluxation of the C1 vertebra on the C2 vertebra are the most common casues. In adults it is more commonly due to a nearby inflammatory lymph node swelling.


Rupture of other tendons. Spontaneous rupture of long tendons occurs in a variety of classic sites, usually on the basis of chronic attrition from occupational stress or local pathology. Presentation is with deformity and weakness rather than as a lump. Common tendons involved are: tendon of extensor pollicis longus at the wrist from excessive use (‘Kettle-drummer’s palsy’) or after Colles’ fracture; spontaneous rupture of extensor tendons of fingers in association with rheumatoid arthritis; and ‘boutonnière’ deformity from rupture of the central slip of extensor digitorum to the middle phalanx. Mallet finger (rupture of distal insertion of extensor digitorum) usually occurs as a hyperflexion sporting injury.





4 Benign or malignant intramuscular neoplasms

Intramuscular lipomas. Lipomas are very common neoplasms and may be found within muscles and between muscle groups. They arise from normal fat and appear during adulthood. Physical signs are usually distinctive. The history is usually of a longstanding and clearly benign lump. Most lipomas are of the subcutaneous type and are well-circumscribed, ovoid masses that are movable. They are also commonly situated in relation to the large muscles of the back. Subfascial and intramuscular lipomas are firmer and more flattened than their subcutaneous counterparts, the edge is more difficult to define and the classic lobulated contour more difficult to detect. Occasionally the lump appears with an acute history after exertion, suggesting extrusion of the lipoma from between muscle groups.


Occasionally lipomas ramify widely and diffusely in tissue planes, especially between muscles (lipoma arborescens). Complete removal is difficult because the lesion extends into surrounding tissue planes and local recurrence is common. This is not a sign of malignancy but of incomplete initial removal. Intramuscular lipomas should be removed surgically to establish the benign nature of the diagnosis beyond doubt.


Fibromatosis. The fibromatoses comprise a group of localised hyperplasias of connective tissues that form nodules with scarring and fibrosis. They may be split into superficial fibromatoses and deep fibromatoses (desmoids — abdominal and extra-abdominal). The superficial category includes variants such as the palmar (Dupuytren’s) and plantar types. They tend to recur locally after removal and form a spectrum from benign conditions to locally malignant tumours. Dupuytren’s contracture is the most benign and well-known form, beginning as a slow-growing palmar nodule in subcutaneous tissue.


‘Desmoid’ tumour (Paget’s tumour). This is a less common form of locally aggressive tumour and usually occurs in the muscles of the anterior abdominal wall. It presents as a firm lump within the rectus muscle of the lower abdomen, often in multiparous women. It requires wide local excision to avoid recurrence (Ch 8.3).


Malignant muscle tumours (fibrosarcoma, rhabdomyosarcoma). Fibrosarcoma is the most common mesodermal tumour of muscle and presents as a painless intramuscular lump. Distal spread occurs late, the lump may be firm or soft and may be vascular and even demonstrate a soft bruit. It can be difficult to distinguish from a benign haematoma without biopsy. CT scanning and more recently MRI are helpful in the diagnosis and delineation of the extent of suspected tumour masses. The lesions are most common on the limbs and may be close to or attached to bone. Smaller tumours present as completely circumscribed and, as they enlarge, tend to become diffusely infiltrative. Other sarcomas such as rhabdomyosarcoma are more malignant and spread locally and systemically at an early stage. Removal of the tumour is necessary for local control. Treatment requires wide local excision after exploration and biopsy. As local spread tends to be within the muscle bundle, excision should encompass the whole muscle involved, from origin to insertion. Consideration needs to be given to excising the whole compartment in which the muscle is found. Chemotherapy and radiotherapy are often also required. Multimodal therapy involving limb salvage surgery combined with adjuvant chemotherapy and radiotherapy may provide survival rates comparable to amputation and chemotherapy, while preserving a functioning limb.



5 Less common causes

Myositis ossificans. Traumatic myositis ossificans occurs after severe soft tissue or bony injury with lifting and disruption of the periosteum at the site of attachment of muscles and ligaments to bone. Calcification and ossification occur within the soft tissue haematoma. Common sites are around the elbow and knee — within the brachialis, deltoid or quadriceps femoris after fractures and dislocations or tendinous avulsions. Patients present with hard, bony lumps, usually attached to bone at the site of tendinous insertions or in continuity with the callus of a fracture. Initially the swelling may have sharp edges and be painful and tender. Later the swelling’s edges become rounded, tenderness diminishes and the lump may regain a degree of mobility on the underlying bone. Joint stiffness is common, but there are no signs of inflammation. Differentiation from an intrinsic bony swelling can be difficult (Ch 6.2). With a primary swelling of bone, the muscles are usually more freely mobile over the lesion. In myositis, muscle function is impaired and the swelling is in continuity with the muscle.


A somewhat similar picture to traumatic myositis can occur with prolonged hypercalcaemia and is due to metastatic calcification. Rarely, in myotonia dystrophica congenita, widespread calcification occurs throughout muscle bellies.


Suppurative myositis (pyomyositis). This is an uncommon condition as normal muscle is resistant to bacterial infection because of good blood supply. It is most common in tropical countries. The quadriceps, iliopsoas and other large muscles are most commonly affected. Painful, fluctuant swellings occur acutely in muscles of limbs or trunk, with signs of local inflammation. Exploration reveals intramuscular abscesses that are often multiple. Culture may be sterile or reveal staphylococci or nonspecific organisms. The lesions may be seen in patients already ill and debilitated with tuberculosis, leprosy or other chronic infective conditions.


Cinchona bodies and other chronic reactions to intramuscular infections more commonly present as subcutaneous lumps. Injections of irritant materials or contaminated injection sites within the gluteal muscles or subcutaneous tissues of the buttocks are followed by chronic inflammatory granulomatous lumps or, occasionally, a chronic thick-walled abscess without overt signs of infection.


Common materials seen in migrant European men and women are quinine (cinchona) bodies and bismuth. Quinine tends to form round or ovoid lumps in subcutaneous fat or gluteal muscles, which are firm and nontender and often exhibit the sign of eggshell crackling on palpation.


Bismuth and other heavy metal injections tend to form deeper and less well defined intramuscular lumps.


X-rays show characteristic findings. Cinchona bodies show a thin rim of calcification in a round or ovoid buttock mass, bismuth shows as radiating converging radio-opaque lines in the line of muscle fibres. Treatment other than reassurance is rarely required.

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Jul 18, 2017 | Posted by in GENERAL SURGERY | Comments Off on Limb problems

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