Abstract
1. One hundred patients with osteochondritis dissecans of the knee have been reviewed. Sixty-eight were male. Unilateral lesions were found in seventy-four. The average age at onset of symptoms was eighteen years.
2. The outstanding etiological feature was found to be direct injury to the joint surface (46 percent), repeated injuries sustained in first class athletics and field sports, and mechanical abnormalities of the knee.
3. Osteochondral fracture was found in seven cases.
4. The results of various types of treatment are described and a plan of management outlined.