[Ulnar parametacarpal flap. Anatomical study and clinical application].

The ulnar border of the hand provides a new skin flap which is very useful in the reconstruction of defects of the palm of the hand and ulnar fingers. An anatomical study of the dorsal carpal branch of the ulnar artery and its various branches has led us to propose the ulnar parametacarpal flap either as a pedicle or free microsurgical transfer. The territory of the dorsal carpal branch of the ulnar artery allows harvesting of a simple sensitive skin flap or a composite flap comprising a bone or tendon island flap. Description of the distal communicating vessels with the ulnar collateral artery of the little finger extends the territory of the ulnar parametacarpal flap; based on a retrograde blood supply, it can reach the dorsal and palmar surfaces of the ulnar fingers. The authors present several clinical applications and define the place of this new flap among the various treatment options for the hand.