Anatomy of the lateral femoral cutaneous nerve related to inguinal ligament, adjacent bony landmarks, and femoral artery

Lateral femoral cutaneous nerve (LFCN) generally emerges from the pelvis behind the inguinal ligament (IL) to the thigh. Because of its proximity to the anterior superior iliac spine (ASIS) and hip joint, the LFCN is prone to injuries during various procedures. Anatomy of this nerve is highly variable among studies. Moreover, measurement data regarding its branches including the differences between genders and sides are still lacking. This study was, therefore, done to clarify these issues. Eighty-five thighs from 43 cadavers of both genders were dissected at the inguinal region. Distances from each branch of the LFCN to palpable landmarks: the ASIS, pubic tubercle (PT) and femoral artery (FA) were measured along the IL. Up to four branches of the LFCN were found; however, the single trunk was the most common form (>65%). The common site of this pattern on the IL was within 2 cm medial to the ASIS but could be present at over 6 cm. The distances in case of bifurcation were mostly comparable to those of the single trunk. In contrast, the values varied considerably in the cases with three or more branches (three cases). Regarding side and gender, asymmetry in the branching pattern was found in one fourth of specimens. However, only some minor differences between genders or sides in the measurement data were seen. These findings suggest that asymmetry and multiple branches of the LFCN should be concerned. The measurement data are also useful for localizing the LFCN with higher accuracy.