Atypical ulnar tunnel syndrome accompanied by sensory disturbance of the dorsal sensory branch of the ulnar nerve.

Abstract

An atypical accessory abductor digiti minimi, which is morphologically a bicipital muscle, was the cause of the ulnar tunnel syndrome. A ganglion grew from the volar carpal joint at the same time and caused sensory disturbance of the dorsal sensory branch of the ulnar nerve.