study of the anatomical course of the lateral femoral cutaneous nerve and its susceptibility to compression

ABSTRACT

The anatomical course of the lateral femoral cutaneous nerve was studied by dissecting twenty cadavers. The skin and subcutaneous tissue was removed from the anterior and lateral sides of the anterior abdominal wall and the thigh. The results of the dissection of the specimens revealed that the lateral femoral cutaneous nerve originated from the first and second roots of lumbar plexus and coursed laterally and downwards across the iliacus muscle to leave the abdomen into the thigh. The site at which the nerve emerged from the abdomen was variable and recorded at five different sites in relation to the anterior superior iliac spine, inguinal ligament and origin of sartorius muscle. Depending on these anatomical sites of exit of the nerve, five types were recorded Type I The nerve crossed the iliac crest posterior to anterior superior iliac spine and constituted about 5% of the dissected specimens. Type II In which the nerve pierced the inguinal ligament just medial to anterior superior iliac spine and constituted about 40% of specimens. Type III The nerve pierced the tendinous origin of sartorius and constituted about 20% of specimens. Type IV The nerve passed into the thigh in the fibro-fatty tissue in the interval between sartorius and iliopsoas muscles deep to inguinal ligament and constituted about 15% of specimens. Type V The nerve passed behind the inguinal ligament in the fibro-fatty tissue in front of iliopspas muscle and constituted about 15% of specimens dissected. Combined types IV and V Were noticed in 5% of specimens. These results showed that the nerve in the first three types [type I, II, and III] was liable to compression against bone [in type I], between slips of inguinal ligament [in type II] or between slips of sartorius muscle [type III]. But in the last two types [type IV and V], the nerve was not liable to compression because it passed through loose fibro-fatty tissue behind the inguinal ligament. The determination of the course of the lateral femoral cutaneous nerve and possible anatomical variations is important to avoid its injury during intramuscular injection, surgery around inguinal region, harvesting bone graft and introducing local anaesthesia