Ulnar nerve compression at the elbow caused by the epitrochleoanconeus muscle: a case report and surgical approach.

Cubital tunnel syndrome is the second most common peripheral nerve compression syndrome. It is the most common peripheral neuropathy of the ulnar nerve. The surgical treatment of the cubital tunnel syndrome is widely described in the literature, however the variations of the standard muscular anatomy in the medial humeral epicondyle region may create technical difficulties during surgical management. The epitrochleoanconeus muscle, which is an aberrant muscle of this region, is a rare cause of cubital tunnel syndrome. A case with ulnar nerve compression at the elbow caused by an uncommon etiological factor, hypertrophic epitrochleoanconeus muscle, and its surgical management is reported.