Osteochondritis dissecans as a cause of developmental dislocation of the radial head.

Osteochondritis dissecans of the capitellum produces an area of focal necrosis that may result in a potentially unstable relationship between the capitellum and the radial head. Seven patients with developmental instability of the radial head secondary to osteochondritis dissecans of the capitellum treated between 1984 and 1995 were studied. All patients were male with an average age of 13 years. The most common symptom was pain with a decrease in range of motion. Patients lacked an average of 24.3 degrees extension. Initial plain radiographs were most helpful for evaluating the relationship of the radial head to the capitellum, and tomography or magnetic resonance imaging were helpful for the detection of loose bodies. The most common direction for instability was posterolateral. Treatment varied from conservative management with nonsteroidal antiinflammatory medication to open reduction and internal fixation of an osteochondral fragment. The average followup was 3.2 years. At latest followup, 11 patients were pain free; however, they lacked an average of 17 degrees extension. Only 2 patients progressed to complete dislocation of the radial head. Developmental instability of the radial head may occur secondary to osteochondritis dissecans of the capitellum. Plain radiographs are sufficient for initial detection and followup. Treatment is determined by the presence of loose bodies and the characteristics of the osteochondral defect. Initial symptoms will resolve; however, lack of extension may persist.