Calcified bodies in popliteal cysts: a characteristic radiographic appearance.

Calcified bodies in popliteal cysts have a characteristic radiographic appearance which can be confirmed by arthrography. Calcified bodies may arise in the true joint due to trauma, arthropathy resulting in joint destruction, or synovial osteochondromatosis. These calcified loose bodies may pass into a popliteal cyst through posterior joint-bursal communications or can arise in a popliteal cyst by chondrometaplasia. Correct radiographic interpretation will exclude soft tissue tumors and vascular lesions as differential considerations. Management of these patients will be determined by the clinical circumstances since neither popliteal cysts nor synovial osteochondromatosis are necessarily symptomatic.