To evaluate the effectiveness of MRI in diagnostic studies and management of synovial chondromatosis involving the hip joint.

From November 1995 to September 1998, 6 patients from 6 cases of synovial chondromatosis involving the hip joint, underwent complete removal of loose bodies and subtotal excision of the synovial membrane.

Preoperatively, all cases had hip pain and 5 cases had limited hip motion. Preoperative MRI revealed target-like lesion in T2 images and synovial hypertrophy. MRI findings revealed lesions in the inferomedial capsular portion in all cases and invading the intrapelvic portion in 2 cases. Pathologic findings revealed Milgram stage II in 5 cases and Milgram stage III in 1 case. It also showed 15 to 350 loose bodies in the diameter of 1 mm to 40 mm. Two cases received reoperations due to recurred lesions with pain 3 to 4 months after the operation. Average Harris Hip Score was 37.8 points preoperatively and 90.8 points in the last follow-up.

For synovial chondromatosis involving the hip joint, MRI contributed to a faster and more accurate diagnosis and aided in surgical planning for complete removal. There was also a need for a radical synovectomy and loose body removal for prevention of recurrence.