A morphometric study of the ulnar nerve in Guyon’s canal

Abstract

Objectives: Guyon’s canal is clinically significant because it contains the ulnar nerve, artery and veins and is a location for compression injury. This study was undertaken to determine the anatomy of the ulnar nerve in Guyon’s canal on 40 wrists of 20 adult formalin-fixed cadavers.

Methods: 40 wrists of 20 formalin-fixed adult cadavers obtained from the Department of Anatomy, Ege University Faculty of Medicine were dissected. In each cadaver, the skin and the subcutaneous fatty tissues were removed starting from the forearm down to the palm of the hand. The palmaris brevis muscle and the palmar aponeurosis were dissected to expose Guyon’s canal.

Results: The length and diameter of the main trunk of the ulnar nerve in Guyon’s canal before dividing into its terminal branches were measured as 11.72±1.99 mm and 3.41±0.5 mm, consequently. Within the canal, the main trunk divided into two terminal branches. The diameter of the deep branch was 1.77±0.47 mm and the superficial branch was 2.41±0.45 mm. The superficial branch divided into the proper palmar digital nerve supplying the medial side of the little finger and the common palmar digital nerve supplying the adjoining sides of little and ring fingers.

Conclusion: An accessory abductor digiti minimi muscle was observed as a possible cause of compression in Guyon’s canal. Despite its clinical relevance, the diameters of the deep and superficial branches of the ulnar nerve in Guyon’s canal do not exist in previous studies. 

Keywords

• morphometry
• ulnar nerve
• ulnar tunnel

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