Year Book: The Dorsal Branch of the Ulnar Nerve: An Anatomic Study

---

Botte, MJ. Cohen, MS. Lavernia, CJ. von, Schroeder HP. Gellman, H. Zinberg, EM. Abstract/Commentary:|1992 Year Book of Hand Surgery. Article 1-4.|Original Article:|J Hand Surg. 1990. 15A. pp 603-607.. Background.--A better understanding of the anatomy and course of the dorsal branch of the ulnar nerve may help prevent nerve injury during surgery. This branch supplies sensibility to the dorsoulnar aspect of the hand, the dorsum of the small finger, and the dorsoulnar aspect of the ring finger. Its size and specific topographic course, however, have not been well delineated. The results of an anatomical study of the dorsal branch of the ulnar nerve were reviewed. Methods.--In 24 fresh adult cadaver upper extremities, the dorsal branch of the ulnar nerve was dissected in a proximal-to-distal direction. Branch points were noted, and the terminal branches were identified. Findings.--The nerve arose from the medial aspect of the ulnar nerve at a mean of 6.4 cm from the distal aspect of the head of the ulna and 8.3 cm from the proximal border of the pisiform. It had an average diameter at origin of 2.4 mm and passed dorsal to the flexor carpi ulnaris, piercing the deep fascia. The nerve became subcutaneous on the medial aspect of the forearm at an average of 5 cm from the proximal edge of the pisiform. The nerve had an average of 5 branches with diameters of 0.7-2.2 mm (Fig 1-4). Conclusion.--With a better understanding of the anatomy of this nerve, surgeons may be able to avoid injuring it during surgical procedures. An improved understanding may also help surgeons to locate the nerve for repair of lacerations or administration of local anesthetics for regional nerve blocks.