Presentation
History of an full ACL rupture and menisectomy 20 years ago. He now presented complaining of increasing pain, painful extension and local stiffness.
Patient Data
The images show several calcified hyaline cartilage nodules in the knee joint itself as well as a large collection of similar calcified nodules just posteromedially to the joint space. These are presumably located in a 'Baker cyst'. These findings are pathognomonic for synovial chondromatosis.
Additionally, osteophytes and joint space narrowing of the knee joint, worst in the medial component, are in keeping with osteoarthritic changes.
Case Discussion
Synovial chondromatosis is the formation of hyaline cartilage nodules in the sub-synovial tissue of a joint, tendon sheath or bursa. The clinical symptoms include pain, swelling and restricted range of motion.
The knee is the most commonly affected joint, but it also occurs in the hip, elbow, shoulder and ankle.
Synovial chondromatosis can be divided into primary and secondary forms. Secondary synovial chondromatosis usually results from mechanical injury to the cartilage and is most frequently related to degenerative arthropathy.
Radiographs show calcification of multiple intra-articular hyaline cartilage nodules in 70 - 95% of cases. Extrinsic bone erosion can be seen, but mostly in less capacious joints such as the hip. Treatment is surgical resection. The recurrence rate after surgery varies from 3 to 23% 1.