Morphometric Study of Martin-Gruber Anastomosis and its Surgical Implications: A Cross-sectional Cadaveric Study

Abstract

Introduction: The Martin-Gruber anastomosis is a median-ulnar nerve communication in the upper part of the forearm. This anastomosis is classified into four types. Aim: To determine the incidence and morphometry of the Martin-Gruber anastomosis and recognise its surgical implications in the South Indian population. Materials and Methods: This cross-sectional study was conducted on 60 cadaveric upper limb specimens obtained from the Department of Anatomy, Rajarajeswari Medical College and Hospital, Bengaluru, Karnataka, India between November 2022 and March 2023. The median and ulnar nerves were traced, and the Martin-Gruber anastomosis was identified and documented. The classification devised by Nakashima T was used in present study. The distance from the medial epicondyle of the humerus to the point of anastomosis on the ulnar nerve was measured using Vernier calipers. The data were analysed using the statistical software Stastistical Packages for the Social Sciences (SPSS) version 23.0. Categorical variables were expressed as frequency and percentage, while continuous data were expressed as mean and standard deviation. Results: The Martin-Gruber anastomosis was observed in 11 out of 60 upper limb specimens (18.33%). Type I anastomosis was observed in 3 specimens (27.27%), Type II in 2 specimens (18.18%), and Type III in 6 specimens (54.4%). Type IV was not documented in present study. The distance from the location of the anastomosis on the ulnar nerve to the medial epicondyle of the humerus ranged from 2.2 cm to 13.2 cm, with an average of 3.5 cm. Conclusion: The findings of present study might be useful for neurosurgeons during nerve transfer techniques for chronic ulnar neuropathy, which is seen in the general population as well as athletes.

Keywords

• chronic ulnar neuropathy
• median-ulnar nerve communication
• nerve transfer techniques