Case report 692: Synovial chondrometaplasia of the 1st costovertebral joint.

Synovial chondrometaplasia, also known as synovial chondromatosis, is a rare disease affecting the synovial membrane and characterized by a nodular proliferation of metaplastic cartilage. It most commonly involves large joints such as the knee, hip, and elbow, but its presence in unusual locations such as small joints and the temporomandibular joint has been described. To our knowledge, this is the first case report of synovial chondrometaplasia involving the costovertebral joint in a patient with a previous injury to that area.