A Cadaveric Study on Radial Nerve Risk Zone in the Distal Part of the Arm

Abstract

Introduction: Injury to the radial nerve in the arm is very frequent following fractures of the shaft of the humerus and may also occur during surgery on the arm. These iatrogenic injuries can be prevented by predicting the point at which the nerve penetrates the lateral intermuscular septum during its course from the posterior-to-anterior compartment of the arm. Aims and Objectives: Our study aims to find out the point of penetration of the radial nerve in the lateral intermuscular septum (radial nerve risk zone [RNRZ]). Materials and Methods: The study was conducted on 30 upper limbs of adult formalin-embalmed cadavers during MBBS undergraduate dissection at the department of anatomy. The posterior aspect of the arm was dissected to expose the radial nerve, and measurements of parameters were recorded. Results: The mean humeral length was 29.91 ± 2.66 cm. The mean distance from the lateral epicondyle of the humerus to the point on the lateral intermuscular septum where radial nerve pierces during its course from posterior-to-anterior compartment was 11.42 ± 1.042 cm, r = 0.368, and P < 0.05 which was statistically significant. The mean (standard deviation) humeral length of both left and right side difference was statistically significant with P = 0.009 (P < 0.05). Conclusion: We believe that our study will help orthopedic surgeons to estimate the point of penetration of radial nerve into the lateral intermuscular septum which is the RNRZ. This minimizes the risk of radial nerve damage during the fixation of the fractured shaft of the humerus.