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 betwee n the capitellum and the radial head, Seven patients with developmenta l instability of the radial head secondary to osteochondritis dissecan s of the capitellum treated between 1984 and 1995 were studied, All pa tients were male with an average age of 13 years. The most common symp tom was pain with a decrease in range of motion, Patients lacked an av erage of 24.3 degrees extension. Initial plain radiographs were most h elpful for evaluating the relationship of the radial head to the capit ellum, and tomography or magnetic resonance imaging were helpful for t he detection of loose bodies, The most common direction for instabilit y was posterolateral, Treatment varied from conservative management wi th nonsteroidal antiinflammatory medication to open reduction and inte rnal fixation of an osteochondral fragment, The average followup was 3 .2 years. At latest followup, 11 patients were pain free; however, the y lacked an average of 17 degrees extension. Only 2 patients progresse d to complete dislocation of the radial head. Developmental instabilit y of the radial head may occur secondary to osteochondritis dissecans of the capitellum. Plain radiographs are sufficient for initial detect ion and followup, Treatment is determined by the presence of loose bod ies and the characteristics of the osteochondral defect, Initial sympt oms will resolve; however, lack of extension may persist.