Meralgia paresthetica caused by entrapment of the lateral femoral subcutaneous nerve at the fascia lata of the thigh: a case report and literature review

Meralgia paresthetica (MP) causes tingling, stinging or a burning sensation in the anterolateral part of the thigh, usually as a result of entrapment of the lateral femoral cutaneous nerve (LFCN) at the inguinal ligament (IL) due to mechanical or iatrogenic injury. However, there are few reports on MP caused by entrapment of the LFCN at a more distal site from the IL. We report here a rare case of MP caused by entrapment of the LFCN at the fascia lata of the thigh level. A 23-year-old man felt numbness and sharp pain at the anterolateral aspects of both thighs soon after direct repair surgery for L5 isthmic spondylolisthesis. Although his symptoms were relieved a few days later, numbness and sharp pain in the right thigh recurred 6 months after the surgery. A diagnosis of MP was made, and decompression of the LFCN was performed because conservative treatment for MP was inadequate. Intraoperatively, it was noted that the LFCN was entrapped underneath the fascia lata of the thigh, not at the IL level. His symptoms disappeared after LFCN was released. This case demonstrates that it is necessary to consider the possibility of entrapment of the LFCN at the fascia lata at the thigh level in MP.