The first dorsal interosseous muscle: an anatomic study.

The anatomy of the first dorsal interosseous muscle, with particular reference to its vascular and nerve supply, was studied in ten fresh cadaveric hands. A constant dorsal and palmar blood supply is identified from four major branches of the radial artery and deep palmar arch. The ulnar nerve innervates the muscle in a pattern that parallels the palmar blood supply. This information provides a basis for the use of the muscle as a local transposition flap.