Incidental Finding of Synovial Osteochondromatosis: A Case Report

Synovial osteochondromatosis (SOC) is a rare, benign condition of unknown etiology characterized by the formation of cartilaginous loose bodies. This often leads to early osteoarthritis with decreased range of motion and pain. Clinical presentation most often is reported as monoarticular pain affecting the knee or less commonly the hip shoulder or elbow. Diagnosis can be confirmed on x-ray imaging where the characteristic synovial bodies will be identified. Management with early debridement of the synovium will often be curative but more complex cases may require further surgical management. We present a 33-year-old male presented with localized left knee pain. Given the history of new-onset pain, left knee x-rays were obtained that revealed a displaced patella with multiple ossific densities around the left knee which were suspicious for a new diagnosis of SOC. Due to its nonspecific symptoms and imaging, the diagnosis of SOC is often delayed or missed. Therefore, prompt diagnosis and treatment are important in order to avoid irreversible cartilage destruction in the joint, prevent the development of chronic pain, and reduce the risk of malignant transformation.