Lateral Femoral Cutaneous Nerve Blockade

Abstract

Lateral femoral cutaneous nerve block (LFCNB) is useful in the diagnosis and treatment of the entrapment neuropathy of the lateral femoral cutaneous nerve (LFCN) known as meralgia paresthetica (MP). MP is used to describe the clinical syndrome of pain, numbness, burning, and paresthesia in the anterolateral thigh associated with compression of this nerve. Most of the patients respond to conservative management, including nerve block. It may also be used for surgical anesthesia and/or postoperative pain control for procedures on the anterolateral thigh such as skin graft harvesting and to alleviate tourniquet pain from lower extremity orthopedic procedures.

The lateral femoral cutaneous nerve is a sensory nerve composed of branches of the lumbar plexus and, in most cases, from L2 and L3 nerve roots. After emerging from the lumbar plexus, the LFCN emerges from under the lateral border of the psoas major muscle then moves parallel to the iliac crest and in an oblique fashion across the iliacus muscle toward the anterior superior iliac spine (ASIS) and exits the lesser pelvis by passing under the inguinal ligament (IL) and into the subcutaneous tissue of the thigh, superficial in most cases; it is susceptible to compression along its course.