The Anatomical Relationship Between the Dorsal Cutaneous Branch of the Ulnar Nerve and the Ulnar Styloid Process with Variations in Forearm Position

摘要

Background: There are significant variations in the anatomy of the dorsal cutaneous branch of the ulnar nerve (DCBUN). The DCBUN is at risk for iatrogenic injury during surgeries around the ulnar side of the wrist. The purpose of this study was to demonstrate the relationship between the ulnar styloid process and the DCBUN and to confirm the DCBUN's change in location with different forearm positions. Methods: We examined 9 fresh frozen cadaveric limbs to establish the course of this nerve. The DCBUN was dissected and traced around the ulnar border of the wrist. The distance from the tip of the ulnar styloid process to the origin of the DCBUN was measured. The distances from the ulnar styloid process to the DCBUN were measured in supination, pronation, and in a neutral position of the forearm. Results: The DCBUN originated on average 4.92 cm proximal to the ulnar styloid process. In all cases, the DCBUN crossed the ulnar distal to ulnar styloid process and it moved more closely to the ulnar styloid process with a forearm position change from supination to pronation. Conclusions: We recommend making a skin incision on the ulnar side around the styloid process with the forearm in supination or neutral position was another method to avoid injury of DCBUN.