We describe an unusual case of ulnar nerve compression (cubital tunnel syndrome) caused by synovial protrusion in primary synovial chondromatosis of the elbow in a 59-year-old man. Magnetic resonance imaging is a useful tool for diagnosing this rare condition. Surgical excision of the intra-articular multiple loose bodies and ulnar nerve decompression were performed. The clinician should be aware of primary synovial chondromatosis as one of the causative factors of cubital tunnel syndrome.
Keywords: cubital tunnel syndrome; elbow; synovial chondromatosis; ulnar nerve.