Surgical significance of the motor fascicular group of the ulnar nerve in the forearm.

The topography of the fascicular group of the ulnar nerve at the wrist and forearm was studied focusing on the motor (muscle) fascicular group. In 109 of 111 specimens studied (98%), the motor fascicular group of the ulnar nerve is located at the ulnar dorsal or straight dorsal position at the wrist and the distal forearm. This motor fascicular group may be identified as a distinct entity up to 90 mm proximal from the level of the radial styloid. The relatively constant location of the motor fascicular group is significant since most lacerations of the major peripheral nerves of the upper extremity are at the distal forearm or the wrist. In the surgical treatment of acute lacerations of the ulnar nerve at these levels, one should direct special attention to the correct identification, matching, and alignment of the motor fascicular group to enhance reinnervation of the intrinsic muscles of the hand.