[Synovial chondromatosis: review of 25 monoarticular cases]

We report 25 patients (20 female) aged 34 to 74 years old, with monoarticular synovial chondromatosis. Affected joints were the knee in 25 cases, the ankle in one case and the elbow in one case. Chronic articular pain was the main symptom, followed by swelling, limitation in motion range, free palpable bodies and symptomatic popliteal cysts. X ray examination showed free calcified osteochondroid bodies in 48% of patients and secondary osteoarthritis in 36%. Bone scintiscan showed an increased focal uptake. All pathological samples had chondroid or osteochondroid nodules; 64% had small blood vessels, thickened with concentric collagen laminae and 20% had isolated chondrocytes. Malignant degeneration was not observed. Surgical or artroscopic synovectomy was the procedure of choice in 20 knees. In the affected elbow and ankle, extraction of free bodies was the sole procedure. No recurrences were observed. It is concluded that synovial chondromatosis must be considered in the differential diagnosis of chronic articular pain and monoarthritis.