Anatomical study of superior cluneal nerve and its estimation of prevalence as a cause of lower back pain in a South African population

Abstract

Background Lower back pain (LBP) remains a common ailment among adult populations and a superior cluneal nerve (SCN) entrapment accounts for 10% of reported LBP cases. The diagnostic criteria of SCN entrapment include anaesthesia of the SCN. This entrapment can be caused by bone procurement procedures but tends to happen more spontaneously and particularly to sportsmen. This study aimed to describe the location of all three branches of the SCN as well as to estimate the prevalence of entrapment which causes LBP. Methods The SCN was identified as it pierced the thoracolumbar fascia and crossed over the posterior part of the iliac crest on both sides of 50 adult cadavers. A sliding dial calliper was used to measure the distance from the posterior superior iliac spine (PSIS) to the SCN and from the midline lumbar spinous processes to the nerve. A total of 400 patient files were used to estimate the prevalence of SCN entrapment in a South African population. Results The branches of the SCN were found to be 72.6 ± 4.2 mm, 76.6 ± 4.4 mm and 79.6 ± 4.4 mm from the PSIS to the medial, intermediate and lateral branches respectively. From the midline to the medial, intermediate and lateral branches – the SCN was found to be 77.9 ± 4.2 mm, 79.6 ± 4.4 mm and 89.5 ± 4.5 mm. It was estimated that the SCN being the cause of LBP to be 28%. Discussion The measurements found in this study correlate with the measurements found in previous studies. However, this study failed to show sex differences and this could be attributed to sampling as well as chance due to human variation. This study estimated the prevalence of an SCN entrapment as a cause of LBP to be 28% compared to previous studies which estimate it to be 10%. The difference seen here can be a consequence of the limitation of this study in that it was conducted in a private practice.