Vascular insufficiency in Okihiro's syndrome secondary to hypothenar hammer syndrome.

The presence of Okihiro's syndrome (congenital thenar hypoplasia and Duane's anomaly) in a patient became clinically significant when a hypothenar hammer syndrome developed. The ulnar artery occlusion resulted in a compromise of the hand's vascular supply because of a congenital hypoplastic radial artery. Resection of the thrombosed ulnar artery and insertion of an interposition vein graft restored circulation to the hand. Anatomic features in this case include a hypoplastic radial artery and double motor branch of the median nerve. Clinicians should consider Okihiro's syndrome in the differential diagnosis of thenar muscle atrophy since there are genetic, diagnostic, and clinical implications.