Morphological Variations of the Tricipital Aponeurosis and Its Clinical Significance: A Cross-sectional Cadaveric Study

Introduction: The radial nerve is commonly injured during posterior approach humerus surgeries, making it crucial for surgeons to identify and preserve the nerve. The tricipital aponeurosis (TA) serves as a reliable landmark for identifying the radial nerve during these procedures. Aim: This study aimed to investigate the different shapes and patterns of the TA and their relationship with the radial nerve, as well as their clinical significance. Materials and Methods: A cross-sectional observational cadaveric study was conducted in the Department of Anatomy, Dr. Chandramma Dayanand Sagar Institute of Medical Education and Research (CDSIMER), a unit of Dayanand Sagar University (DSU), Bengaluru, Karnataka, India, from January 2022 to April 2022. A total of 40 arms from 20 adult cadavers obtained from CDSIMER were examined. The TA was assessed to record variations in its shape and classified accordingly. The distance of the radial nerve from the point of confluence was measured for different types. Vernier calipers were used for all measurements. The collected data was analysed using the Statistical Package for the Social Sciences (SPSS) version 16.0, and paired two-tailed Student's t-test was performed. Results: The classical type A was observed in 32 (80%) of the specimens. The mean distance of the radial nerve from the point of confluence of the TA was 30.58±4.29 mm on the right side and 31.27±4.48 mm on the left side, with a p-value of 0.621. Conclusion: Knowledge of the different shapes of the TA and its distance from the radial nerve can assist surgeons in creating a safe zone during various procedures, thereby preventing radial nerve injuries.