Virginia Research Day 2022

Medical Student Research Biomedical

10 Obturator Nerve Macroanalysis And Its Association With Laterality

Alexandra Morgan 1 ; Alekhya Peruri 1 ; Mason Yount 1 ; Jonathan Millard 1 Kelly Roballo 1 Corresponding author: Agreen01@vcom.edu

VCOM Virginia

Introduction: Reinnervating damaged peripheral nerves in the setting of injury is a complex and often unsuccessful procedure. Current medical practice involves the use of autologous nerves, donor nerves or similar replacements leading to inconsistent resuscitation of peripheral tactile sensation and motor function. The unknown longitudinal fascicular organization may provide an explanation for poor outcomes. Analysis of nerve morphology prior to replacement could lead to more accurate and successful transplantation. This study aims to develop a method to conclude which nerve morphology is best suited for each peripheral nerve injury. Recent studies have focused primarily on the sciatic nerve, but little is known regarding obturator nerve morphometry and morphology. The obturator nerve is a branch of the lumbar plexus responsible for sensory innervation to the medial thigh and motor innervation to the adductor muscles. Further exploration into the variability of fascicular arrangements may

reveal patterns which could influence graft selection. Methods: This analysis will focus on donor and recipient laterality with regards to fascicular organization, nerve diameter, fascicle count, nerve length, and leg and tibial bone length. Left and right obturator nerves (N=25 donors) were dissected and harvested from male and female cadavers. Each obturator nerve was separated into nine cross sections. Macroscopic images were taken of individual cross sections using a 20X magnification microscope (OM4724). Leg length was determined by measuring the distance between the anterior superior iliac spine to the tibial prominence. Nerve length was measured after isolation. Nerve diameter and fascicle count were quantified with ImageJ software. Results: Preliminary analyses showed a significant decrease in overall fascicle count in the right obturator nerve (mean=10.17) relative to the left (mean = 11.21), with

p-value 0.09287, significant at p < .10. Diameter were similar in both left and right with overall left 2.28 mm and right 2.29 mm. Nerve length was similar in both left and right (left= 10.83 mm; right 10.86 mm) with no statical significance. These findings were mirrored in both female and male subgroups. There were no differences in leg and tibial bone length with regards to laterality. Conclusion: Fascicle number differences between the left and right side may suggest an innate or developed etiology. Preferential use of one leg over the other may produce lateral differences. Overall, differences in fascicle count between left and right obturator nerves may suggest the need for donor nerves to be harvested from their corresponding side to improve transplant outcomes. Future analyses will use morphometry to establish longitudinal fascicular patterns between left and right obturator nerves.

42