Arthroscopic treatment of synovial chondromatosis that possibly developed after open capsular shift for shoulder instability.

Synovial chondromatosis is a rare disease with an unknown etiology, and can be defined as a synovial process characterized by the formation of metaplastic cartilaginous foci inside the connective tissue of articular surfaces. The disease is classified as primary or secondary. The cause of primary disease is unknown, but its pathogenesis involves the development of chondroid foci in synovial membranes. Secondary disease is caused by synovial tissue pathophysiologies, such as, trauma or infection, adjacent to an involved joint. Plain radiographs reveal multiple calcific nodules in glenohumeral joints. However, X-ray diagnosis is often delayed and extremely difficult when the disease is not calcified. Magnetic resonance imaging (MRI) and computed tomography are helpful. For treatment, open or arthroscopic synovectomy and loose body removal are recommended. The authors experienced a rare case of radiologically non-visible synovial chondromatosis, which was viewed as the cause of postoperative residual pain and limitation of motion in a young male with open capsular shift. This case report is presented to emphasize the role of arthroscopy and MRI in the early diagnosis and treatment of synovial chondromatosis.