65 - Divergence in the Median Nerve: Exploring Anatomical Variations, Demographics, and Clinical Implications

Poster Board Number: 65
There are separate poster presentation times for odd and even posters.
Odd poster #s – first hour
Even poster #s – second hour

Co-authors:

Alfredo Torres-Rodríguez - Sam Houston State University College of Osteopathic Medicine; Norman Ramirez - Mayagüez Medical Center; Mario Loomis - Sam Houston State University College of Osteopathic Medicine; Jailenne Quiñones Rodríguez - Sam Houston State University College of Osteopathic Medicine

Abstract Body : There has been well-documented evidence of median nerve (MN) variations at different anatomical regions of the upper extremity. The prevalence of variations, such as ethnicity and sex, has been observed within a demographic framework. These variations may have clinical implications, particularly in medical procedures, surgical interventions, and the assessment of nerve-related conditions, including compression syndromes, iatrogenic nerve damage, and soft tissue injection. Our study aims to identify variations in the course of the MN from its origin to the anterior interosseous nerve (AIN), to analyze the demographic prevalence and significant clinical implications in minimally invasive procedures.

Twenty-two donors were included (11 female and 11 male). Donors' upper limbs were dissected bilaterally to assess the MN from the origin of the contribution of nerve fibers from both the lateral and medial cords of the brachial plexus along its course before reaching the wrist. The donor ethnicities include African American and Caucasian. Measurements and photos were taken. The measurements between anatomical structures were taken in millimeters (mm) in the arm from the origin between the lateral and medial cord, in the forearm between the medial and lateral epicondyles, and at the branching point of the AIN. Lanz's classification system was used to analyze the course of the MN. Mann-Whitney U test was performed using GraphPad Prism.

We assessed demographic- and sex-related median nerve variations in the arm and forearm. The results demonstrated that the distribution of the MN in males significantly increased (p< 0.0002) in the forearm compared to females. However, the association between the distribution of the MN through ethnicity was not statistically significant. The discernment of these median nerve variations, as illustrated in this cadaveric study, signifies the imperative need for caution when approaching this area in males, challenging conventional anatomical dogma and anticipating potential variations. Understanding the frequency of variations in the median nerve and its surrounding structures across diverse populations and genders will help guide physicians in procedures, such as soft tissue injections, to minimize the risk of iatrogenic nerve injury and maximize positive outcomes.