Reliable techniques to avoid damaging the superficial radial nerve due to percutaneous Kirschner wire fixation of the distal radius fracture through the radial styloid process

Abstract

The use of percutaneous Kirschner wires for fixation of unstable fractures of the distal radius has been widely accepted as the least invasive procedure. However, the injury to the superficial branch of the radial nerve (SBRN) is common. Our purpose in this study was to develop a reliable technique to avoid damaging the SBRN. Twenty cadaver forearms were dissected to identify the SBRN distribution, and 18 forearms were used to undergo placement of three Kirschner wires (KW-A, KW-B, and KW-C). The KW-A, KW-B, and KW-C were driven in the frontal plane into the distal radius, and KW-A and KW-C through the tip of radial styloid process at different angles. The SBRN distribution and its relationship with the KW insertion were identified. Fifty-three patients with unstable distal radius fractures were fixed with external fixator and augmented with 1-3 KW, and the injury rates of SBRN were evaluated. We found a blind region of the SBRN bound by its first bifurcations into radial and ulnar branches and the line crossing the tip of the styloid process. The mean distance of the three wires (KW-A, KW-C, and KW-B) to the closest nerve branch was 4.5, 4.4, and 3.4mm, respectively. The injury of SBRN occurred in two of 53 patients. The injury rate of the SBRN can be effectively reduced when the Kirschner wire is placed along the curve AB and as in proximity to the TRSP as possible under fluoroscopic guidance. Our pinning technique is therefore reliable and practical.