OSTEOCHONDROSES

Osteochondroses (idiopathic avascular necrosis) are non-infective, non-inflammatory disorders of any bone, due to focal ischemic necrosis of growing epiphyses or ossification centers.

Clinically, these disorders are common in adolescents (except Legg-Calve-Perthes disease) and present with localized, constant or intermittent pain at the site of affection, without signs of inflammation. Almost all

osteochondroses are self-limiting and need to be treated symptomatically with temporary immobilization.

While osteochondroses involving almost every long bone or spine have been described, some common lesions are as follows:

Legg-Calve-Perthes disease (LCPD) represents avascular necrosis of femoral capital epiphysis due to unknown etiology, probably related to some hypercoagulation defect.

More common in males (5:1) and pre-adolescents (2-12 years), LCPD presents with mild intermittent pain in anterior thigh or painless limping gait. Diagnosis is radiological, to demonstrate shape and size of femoral head and surrounding osteoarthritis.

Most cases recover spontaneously and need only symptomatic treatment. However, severe, non-resolving cases may need limb immobilization in abduction or surgical correction.

Slipped capital femoral epiphysis (SCFE) is predomi­nantly a disorder of obese or rapidly-growing adoles­cents, probably related to hormonal changes. Endocrinal defects, e.g. hypothyroidism or growth hormone defi­ciency are common in rare pre-adolescent cases.

Clinical presentation depends on severity of slippage. Acute SCFE presents with severe hip pain during attempted motion, while chronic cases develop antalgic (painful) gait and external rotation of affected leg.

Diagnosis is radiological with: (a) widening of epiphysis during pre-slip phase, (b) anterior rotation of femoral neck, and (c) slipped capital femoral epiphysis outside the acetabulum.

Treatment aims to prevent further slippage, by surgical closure of CFE, i.e. epiphysiodesis. Untreated cases may develop complications like osteonecrosis (avascular necrosis of head) and chondrolysis (degeneration of articular cartilage of hip).

Osteochondritis dissecans, i.e. separation of a part of articular cartilage and subchondral bone at certain joints, e.g. knee, ankle and elbow, is usually seen in late adolescence.

Clinically, these cases present with recurrent pain, swelling of affected joint along with its locking in flexed position. Frequently, the loose part may be palpable with changing position (Joint mouse).

Diagnosis is based on X-ray or arthroscopy to detect loose segment. While partially separated part may be re­fixed, completely loose segment needs surgical removal to prevent further articular trauma.

Scheuermann's disease, i.e. osteochondrosis of vertebral bodies is the third commonest cause of spinal deformities in adolescents, after infections and idiopathic scoliosis. Mostly seen in early adolescence, these cases present with thoracic kyphosis and typical tightening of hamstrings. X-ray reveals wedging of affected vertebrae. Correct body posture, exercises and orthotic supports are usually enough to improve the posture and surgery is rarely indicated.

Osgood-Schlatter's disease, i.e. osteochondritis of apophysis of tibial tubercle, presents with knee pain without other signs of inflammation, usually in adolescent boys. X-ray may reveal hyperdensity and/or fragmentation of upper tibial apophysis. Treatment is symptomatic, with spontaneous recovery in 1-2 years.

Sever disease, i.e. osteochondrosis of calcaneum presents with heel pain and tenderness in early adolescence (10-15 years). It appears to be related to repeated stress at the site of tendoachilles insertion. Treatment is symptomatic, with rest and POP cast for 3-4 weeks.

Panner's disease, i.e. osteochondrosis of capitellum, is most common in adolescence, predominantly related to sport­injury, e.g. ball-throwing. It presents with local elbow pain, crepitation and restricted pronation-supination movements. Diagnosis is based on X-ray or MRI and treatment is conservative with restriction of activities. Surgical intervention is indicated only if overlying cartilage is disrupted or fragmented.

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