Osteochondroma and secondary synovial osteochondromatosis

Secondary synovial osteochondromatosis (SOC) is a rare disorder caused by a variety of joint disorders. Two unusual cases of secondary SOC are present ed. The first patient is a 43-year-old man with extensive SOC developing wi thin a bursa surrounding an osteochondroma of the pubic bone. The second pa tient is a 23-year-old man who developed florid and progressive SOC of his hip joint following excision of a femoral neck osteochondroma. SOC recurred despite three excisions over a 15-month period. Imaging was useful in pre- operative diagnosis of bursal SOC in the first patient and in detecting mul tiple recurrences in the second patient. Both cases illustrate prominent SO C developing secondary to osteochondroma. The different hypotheses regardin g bursal and secondary SOC are reviewed.