Solitary synovial osteochondroma of the knee: mimicking a giant loose body

Solitary synovial osteochondromas are rarely seen. Usually arising from the juxta-articular soft tissues without attaching to the bone, these lesions can be large and show clinical and radiological features of a malignant process. This report is about a 64-year-old woman with no history of trauma. She had a history of dull pain and a progressive limited range of motion that had been ongoing for 3 years. An unusual presentation of an uncommon disease that is not widely known by orthopedic surgeons is reported.