1. Osteochondromatosis is a benign condition, probably neoplastic, involving the synovial membranes of joints, bursae, and tendon sheaths, in which cartilage develops by metaplasia of the connective-tissue cells of the membrane.
2. Repeated slight traumata may well be an etiological factor, although infection probably is not.
3. There may be an individual predisposition toward neoplasia.
4. All accessible loose or pedunculated bodies should be removed surgically, because of the discomfort to the patient and the danger of secondary osteo-arthritis, which is a frequent complication.
5. If the process in a knee joint appears active in the synovial membrane at the time of operation, synovectomy should be done.
6. Unsatisfactory postoperative results are usually due to osteo-arthritic changes in joint-surface contours, and not to loose bodies.
7. Spontaneous disappearance of loose bodies may occur.
8. Negative findings on microscopic examination of the synovial membrane do not necessarily negate a diagnosis of osteochondromatosis, for the process may have completed its cycle and the membrane resumed its normal appearance.