Round # 12

• Back to Clinical History and Radiographs
• Back to Radiographic Findings

Diagnosis and Discussion

Correct Diagnosis: Synovial Osteochondromatosis

Discussion:
Synovial osteochondromatosis (SO) is a rare condition characterized by the gradual ossification of intra-articular cartilaginous structures. It is more commonly seen in men, and often appears in the 4^th and 5^th decades of life. The disease is usually monoarticular, with the knee being most commonly affected site. Several small series and case reports, however, have described involvement in many locations, including the shoulder, hip, ankle, and temporomandibular joints.

While primary idiopathic SO is a rare condition, secondary SO is more commonly seen in patients with osteoarthritis. In these patients, SO manifests radiographically as multiple osteocartilaginous loose bodies in the setting of characteristic OA changes in the adjacent joint. The pathology of these lesions is that of chondroid metaplasia, and though extremely rare, malignant transformation to synovial chondrosarcoma can occur. Because of the presence of foreign bodies in the joint, treatment of the pain, swelling, and motion restriction is usually treated surgically with synovectomy and loose body removal. When possible, these procedures can be done arthroscopically.

References:

1. Wittkop B, Davies AM, Mangham DC. Primary synovial chondromatosis and synovial chondrosarcoma: a pictorial review. Eur Radiol 12(8):2112-9, 2002.
2. Fowble VA, Levy HJ. Arthroscopic treatment for synovial chondromatosis of the shoulder. Arthroscopy 19(1):E2, 2003.
3. Resnick D. Tumors and Tumor-like Lesions of Soft Tissue. In: Resnick D, ed. Diagnosis of Bone and Joint Disorders 4^th ed. Philadelphia, London, Toronto, Montreal, Sydney, Tokyo: Saunders, 4204-4207, 2002.

(top of page)

All information contained within the Johns Hopkins Arthritis Center website is intended for educational purposes only. Physicians and other health care professionals are encouraged to consult other sources and confirm the information contained within this site. Consumers should never disregard medical advice or delay in seeking it because of something they may have read on this website.