synovial osteochondromatosis (SOC)

A joint abnormality characterized by the presence of cartilagenous & osseous loose bodies within the synovial cavity in the joint. The etiology is uncertain; however, the primary type may be secondary to synovial metaplasia & the secondary type a result of fractures of osteophytes or articular cartilage shed into the joint cavity. A plain radiograph may show only joint effusion if the fragments are not ossified or may show multiple intra-articular ossified bodies. Magnetic resonance imaging (MRI) allows visualization of ossified & non ossified intrarticular fragments as well as the soft tissue around the joint.

References

Basic Radiology, Chen MYM, Pope TL & Ott DJ (eds), McGraw Hill, NY 1996