Sciatic Nerve Anatomical Relationship with the Piriformis Muscle and its Point of Division

Abstract

The objective of this study is to examine the course of the Sciatic Nerve (SN) and identify anatomical variations 1) between SN and the piriformis muscle (PM), and 2) in SN's point of division into the common peroneal and tibial nerves. The anatomical relationship between SN and PM was classified based on Beaton and Anson's six types of classification, finding 96.3% of the 82 lower limbs followed a typical anatomical relationship (type I), and 3.7% of the lower limbs showed one branch of SN piercing through the PM with the other branch running posterior to PM (type II). No incidence of the other types was found. As for SN's point of division, the mean division distance is expressed ± confidence intervals for all lower limbs (10.54±1.47cm), right (11.52±2.44cm), left (9.57±1.60cm), male (10.27±2.17cm), and female lower limbs (10.89±3.86cm). The median division distance is calculated with an interquartile range (lower limit, upper limit) as 8.30cm (6.15,13.10) for all lower limbs, 8.55cm (6.30,15.17) for right and 8.20cm (6.10,10.91) for left lower limbs, 9.10cm (6.56,13.10) for male and 7.60cm (5.75,12.42) for female lower limbs. A significant difference was not found in SN's mean division distance between right vs. left lower limbs (p‐value = 0.19) and male vs. female (p‐value = 0.68).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.