Familial polyarticular osteochondritis dissecans masquerading as juvenile rheumatoid arthritis

A boy with polyarticular osteochondritis dissecans presented with clinical features of juvenile rheumatoid arthritis. Examination of the synovial fluid of an involved joint demonstrated inflammatory characteristics. Osteochondritis dissecans was present in the patient's mother and brother. Human leukocyte antigens HLA A-2, BW-15 and CW-4 were identified in the affected individuals.