Fracture-dislocation of the base of the fifth metacarpal associated with injury to the deep motor branch of the ulnar nerve: a case report.

Traumatic neuropraxia of the deep motor branch of the ulnar nerve after a fracture-dislocation of the fifth metacarpal is reported. Salient anatomy is discussed and the diagnostic tests necessary to identify this lesion are described. Residual effects of the injury consisted of only a mild wasting of the first dorsal interosseous muscle. The patient had complete functional recovery 4 months after the initial injury.