RÉSUMÉ
Primary synovial chondromatosis is a rare, benign, proliferative disease of hyaline cartilaginous bodies within the synovium of joints. We report a rare case of primary synovial chondromatosis diffusely affecting the ulnohumeral joint causing pain and motion limitations with extrusion into the cubital tunnel and compressing the ulnar nerve but without any preoperative signs or symptoms of ulnar nerve compression. The patient was successfully treated with an open synovectomy to limit disease progression and improve motion. This case highlights that synovial conditions of the elbow may involve the ulnar nerve even when a patient is asymptomatic. Preoperative use of magnetic resonance imaging of the elbow should be considered in patients undergoing either an open or arthroscopic synovectomy.