Elsevier

Hand Clinics

Volume 23, Issue 3, August 2007, Pages 283-289
Hand Clinics

Ulnar Nerve Anatomy

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The anatomy of the ulnar nerve is described from its origin at the brachial plexus to its termination in the hand and digits. The critical anatomy surrounding the cubital tunnel and Guyon canal is emphasized, and clinically relevant anatomic variations, muscle anomalies, and peripheral nerve anastomoses are described.

Section snippets

Anatomy of ulnar nerve at elbow

In the upper arm, the ulnar nerve lies posteromedial to the brachial artery. It then traverses the medial intermuscular septum posteriorly, passing through the arcade of Struthers approximately 8 cm proximal to the medial epicondyle (Fig. 1) [1]. This arcade comprises a band of deep brachial fascia that attaches to the intermuscular septum, has a V-shaped opening, and covers the ulnar nerve for an average length of 5.7 cm [2]. As shown both anatomically and electrophysiologically, the arcade of

Anatomy of the ulnar nerve in the forearm

The ulnar nerve descends down the arm, deep to the FCU on the surface of the flexor digitorum profundus. At the junction of the middle and distal third of the forearm, the ulnar nerve passes ulnar to the ulnar artery and both lie subjacent to the FCU. The palmar cutaneous branch of the ulnar nerve, also termed the “nerve of Henle,” is referenced sparingly in most anatomic textbooks (Fig. 3) [22]. McCabe and Kleinert [23] described the nerve of Henle most typically to originate 16 cm proximal to

Anatomy of the ulnar nerve at the wrist and hand

The main or volar trunk of the ulnar nerve continues subjacent to the FCU and becomes relatively superficial, covered by fascia and skin. The ulnar nerve and artery enter Guyon's canal, which is a fibro-osseous tunnel formed between the pisiform and hamate hook (Fig. 4). The floor of the canal is formed by the pisohamate ligament, and the roof is the superficial volar carpal ligament. Within Guyon's canal, the ulnar nerve bifurcates into superficial and deep branches. The ulnar artery lies

Ulnar nerve anastomoses

Two commonly mentioned nerve variations must be recognized because they are apt to confuse the diagnosis of ulnar nerve dysfunction, resulting in delayed or erroneous treatment. The first is the Martin-Gruber anastomosis in the forearm. With this anomaly, there is a communication between the ulnar nerve and the median nerve in the forearm. The point of connection can be anywhere from 3 to 10 cm distal to the medial epicondyle [48]. With a typical Martin-Gruber anastomosis, the motor nerves that

Summary

The anatomy of the ulnar nerve in the upper extremity is complex because of its passage through various confined spaces. Knowledge of the local, often variable, anatomy is essential for accurate diagnosis and successful treatment of ulnar nerve dysfunction. Surgical management requires a thorough exploration and complete release of all potential sites of compression when treating neuropathies of the upper extremity. Particular attention should be directed toward identifying and addressing

Acknowledgment

The authors thank Jill K. Gregory, MFA, CMI, medical illustrator, and Dori Kelly, MA, senior editor.

References (49)

  • R.E. McCarthy et al.

    Anomalous volar branch of the dorsal cutaneous nerve: a case report

    J Hand Surg [Am]

    (1980)
  • C.L. Hankins et al.

    A variant of Kaplan's accessory branch of the dorsal cutaneous branch of the ulnar nerve: a case report and review of the literature

    J Hand Surg [Am]

    (2005)
  • R.A. Meals et al.

    Variations in the digital sensory patterns: a study of the ulnar nerve-median nerve palmar communicating branch

    J Hand Surg [Am]

    (1983)
  • G.P. Ferrari et al.

    The superficial anastomosis on the palm of the hand between the ulnar and median nerves

    J Hand Surg [Br]

    (1991)
  • M. Fahrer et al.

    Ulnar compression neuropathy due to an anomalous abductor digiti minimi: clinical and anatomic study

    J Hand Surg [Am]

    (1981)
  • J.M. Failla

    The hypothenar adductor muscle: an anomalous intrinsic muscle compressing the ulnar nerve

    J Hand Surg [Am]

    (1996)
  • M.H. Greene et al.

    Bipartite hamulus with ulnar tunnel syndrome: case report and literature review

    J Hand Surg [Am]

    (1981)
  • A.B. Grundberg

    Ulnar tunnel syndrome

    J Hand Surg [Br]

    (1984)
  • P.P. Belliappa et al.

    Excision of the pisiform in piso-triquetral osteoarthritis

    J Hand Surg [Br]

    (1992)
  • Y. Uchida et al.

    Electrodiagnosis of Martin-Gruber connection and its clinical importance in peripheral nerve surgery

    J Hand Surg [Am]

    (1992)
  • M. Spinner

    Injuries to the major branches of peripheral nerves of the forearm

    (1978)
  • D.B. Polatsch et al.

    Severe ulnar neuropathy after subcutaneous transposition in a collegiate tennis player

    Am J Orthop

    (2002)
  • H.J. Clemens

    Zur morpholigie des ligamentum epitrochleoanconaeus

    Anat Anz

    (1957)
  • W. Wachsmuth et al.

    The musculus epitrochleoanconaeus and its clinical significance

    Monatsschr Unfalheilkd Versicher Versorg Verkehrsmed

    (1968)
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