Anatomical course of the lateral femoral cutaneous nerve and its susceptibility to compression and injury.

The anatomy of the lateral femoral cutaneous nerve was investigated through dissection of 52 human anatomic specimens. The variability of its course and locations as it exists the pelvis is described and related to soft-tissue and bony landmarks. Five different types are identified: type A, posterior to the anterior superior iliac spine, across the iliac crest (4 percent); type B, anterior to the anterior superior iliac spine and superficial to the origin of the sartorius muscle but within the substance of the inguinal ligament (27 percent); type C, medial to the anterior superior iliac spine, ensheathed in the tendinous origin of the sartorius muscle (23 percent); type D, medial to the origin of the sartorius muscle located in an interval between the tendon of the sartorius muscle and thick fascia of the iliopsoas muscle deep to the inguinal ligament (26 percent); and type E, most medial and embedded in loose connective tissue, deep to the inguinal ligament, overlying the thin fascia of the iliopsoas muscle, and contributing the femoral branch of the genitofemoral nerve (20 percent). The results of this study suggest that the lateral femoral cutaneous nerve is most susceptible to mechanical trauma when the nerve is type A, B, or C.