Arthroscopic management of synovial chondromatosis of the knee. Findings and results in 18 cases.

We report the results of arthroscopic removal of loose bodies and abnormal synovium from 18 knees with primary synovial chondromatosis. After a mean of three years, six months (range one to 10 years), 14 knees were either symptom-free or had only minor symptoms. Three of these had required two arthroscopic operations. Three patients were improved but not cured and there was one failure. The results were better than the published results of open operation for this condition. Three patterns of macroscopic appearances were noted: four knees had large lesions covered by normal synovium, 10 had small fragments of cartilage lying in or on the synovium and four had only free fragments of cartilage in the joint cavity but none in, on, or under, the synovium. These three appearances may represent three different disease processes.