|
Synovial osteochondromatosis (SOC) (synonyms include synovial chondromatosis, primary synovial chondromatosis, synovial chondrometaplasia) is a rare disease that creates a benign change or proliferation in the synovium or joint-lining tissue, which changes to form bone-forming cartilage. In most occurrences, there is only one joint affected, either the knee, the hip, or the elbow. Rarely involves the TMJ.〔Fuller E, Bharatha A, Yeung R, Kassel EE, Aviv RI, Howard P, Symons SP. Case of the month #166: synovial chondromatosis of the temporal mandibular joint. Canadian Association of Radiologists Journal. 2011 May; 62(2):151-153.〕 The etiology or cause is unknown. In this condition, cartilaginous metaplasia takes place within the synovial membrane of the joint. Metaplastic synovium organizes into nodules. With minor trauma, nodules are shed as small bodies into the joint space. In some patients, the disease process may involve tendon sheaths and bursal sacs. Cartilaginous intra-articular bodies float freely within the synovial fluid, which they require for nutrition and growth. Progressive enlargement and ossification occur with time. If they remain free, they continue to grow larger and more calcified. In severe cases, they may occupy the entire joint space or penetrate to adjacent tissues. Also, they can deposit in the synovial lining, reestablish a blood supply, and become replaced by bone. On occasion, synovial reattachment can lead to complete reabsorption of the cartilage fragment. ==Classification== Classification is divided into primary versus secondary SOC. Primary SOC occurs in an otherwise normal joint. It is suggested by monoarticular involvement in a patient in the third to fifth decades of life. Secondary SOC occurs in older patients in joints previously affected by joint disease such as osteoarthritis. This pattern is suggested by bilateral involvement with multiple joint intra-articular bodies. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Synovial osteochondromatosis」の詳細全文を読む スポンサード リンク
|