Synovial osteochondromatosis of the sternoclavicular joint.

A 9-year-old boy with a rare localisation of synovial osteochondromatosis at the left sternoclavicular joint is presented. Synovial osteochondromatosis at this site and at this age has not been previously reported. Joint loose bodies were removed surgically and partial synovectomy was performed. Follow-up showed no evidence of recurrence over a period of 8 years.