DISTAL RADIAL AND ULNAR LANDMARKS USED IN PERCUTANEOUS PIN FIXATION: ANATOMICAL RELATIONSHIP TO THE SUPERFICIAL RADIAL AND ULNAR NERVES

Abstract

The radial and ulnar styloids as well as Lister's tubercle are important surgical landmarks in the surgical treatment of distal forearm fractures. There have been limited studies assessing their relative safety in terms of their distance from superficial nerves which are in danger during surgical procedures. The aim of this cadaveric study was to assess and compare the distance of superficial nerves to these important surgical landmarks. Twenty embalmed cadaveric upper limbs were dissected exposing the nerves and tendons around the wrist. The radial styloid, Lister's tubercle, ulnar styloid and nerve branches were marked with pins. The distance of the nearest nerve branch to each landmark was measured with a digital calliper. Statistical analysis of the data was performed using SPSS for Windows 11.5 (SPSS Inc., Chicago, IL) using Friedman Tests and Wilcoxon Signed Ranks tests. The median distance of the nearest nerve branch to the radial styloid was 5.42 mm, to the Lister's tubercle was 16.68 mm and to the ulnar styloid was 13.56 mm. There was unequal safety for these three surgical landmarks regarding proximity to nerve branches (p < 0.00001). Paired comparison using Wilcoxon Signed Ranks Test showed that the Lister's tubercle was safer than the radial styloid (p < 0.0001) and ulnar styloid (p = 0.04). In addition, the ulnar styloid was safer than the radial styloid (p < 0.001). There is a higher risk of injury to superficial nerves when operating near the radial styloid as it is significantly closer to nerve branches as compared to Lister's tubercle and ulnar styloid.