Primary synovial osteochondromatosis of the ankle: A case report and review of the literature.

Primary synovial osteochondromatosis of the ankle is a rare and benign disease of the young adult. It is characterized by the formation of multiple nodules of hyaline cartilage under the synovium. It is usually asymptomatic but can sometimes be revealed by pain or joint mobility disorders. X-rays and CT scans can easily diagnose calcified osteochondromas, but ultrasound and MRI can provide a quicker diagnosis by visualizing non-calcified foreign bodies. Surgery under arthroscopy remains the best therapeutic choice, however, this pathology still causes recurrence in less than 1/3 of cases.