Anatomically high division of sciatic nerve and its clinical significance

Background / Aim : The sciatic nerve (SN) is a mixed nerve formed in pelvis by joining of L4-S3 anterior spinal nerve roots. SN can be under the pressure in different regions throughout its course, however, the most frequent site of impingement is under the piriformis muscle which causes occurrence of piriformis syndrome. High division of SN has its relevance considering the fact that it leads to compression of nerve resulting in piriformis syndrome. Determining the connection between anatomical parameters of pelvis and high division of SN which is considered to be one of the most common causes of piriformis syndrome in both genders. Methods : This study was conducted on 28 formalin fixed cadavers of both genders at the Institute of Anatomy in Belgrade and Department of Anatomy in St Andrews. For measuring of required dimensions, we used a ruler and a caliper. The statistical data analysis was performed in SPSS 11.0 using Mann-Whitney U test . A statistically significant difference in the values of bispinal and bituberal lines were observed. Results : A high division of SN was found on 58.33% of the male cadavers and 80% of the female cadavers. A statistically significant difference in the mean value of the bituberal line between the male and female sex was also recognised. Conclusion : Connection between the anatomical parameters of the pelvis and the level of division sciatic nerve is confirmed. Although on the basis of the results it could be assumed that people with smaller pelvic dimensions would have greater likelihood of developing a piriformis syndrome. The other factors such as biomechanics related to a wider „Q angle“ in women that could result in a higher incidence of piriformis syndrome, should also be considered.