Anatomical variability of the lateral femoral cutaneous nerve: findings from a surgical series

The lateral femoral cutaneous nerve (LFCN) is a branch of the lumbar plexus and supplies the skin of the lateral thigh region. This entrapment-compressive syndrome is named meralgia paresthetica or Roth's meralgia and depends, on a vast majority of cases, on the entrapment of the nerve in proximity of the inguinal ligament. Surgical decompression of the nerve is an option when conservative treatments fail and is usually performed through a 3-cm infrainguinal skin incision. Available data on anatomical variations of the LFCN derive from extensive cadaver dissections and lack many features relevant to the surgeon. This study was conducted to investigate anatomical details of the LFCN at the site of surgery for meralgia paresthetica. We reviewed retrospective data regarding the anatomical features of LFCN from 148 consecutive patients operated on for Roth's meralgia. In the majority of the cases the LFCN was a single trunk, deep to the thigh superficial fascia and to the inguinal ligament and coursing inferior-lateral to the anterior superior iliac spine. Less frequent findings were early nerve bifurcation, epifascial position, inferior-medial direction, and exit from the pelvis through an iliac bone canal. In 13 cases (8.8%) the nerve was not found at surgery. Anatomical variations of the LFCN must be considered at the time of surgery to maximize success rates and avoid nerve damage during surgical dissection.