Cubital canal syndrome due to subanconeus muscle

A forty-nine-year-old patient, suffering from right cubital canal syndrome, was admitted for surgery. The diagnosis was established clinically and by subsequent electromyography. The factor producing pressure on the ulnar nerve was the subanconeus muscle, an auxiliary extension of the medial portion of the triceps muscle, arising from the medial border of the olecranon and adjacent triceps tendon and inserting into the dorsal aspect of the medial epicondyle. Complete excision of this muscle is sufficient, leading to immediate improvement in most cases.