Intrapelvic and thigh-level femoral nerve lesions: management and outcomes in 119 surgically treated cases

Abstract

Object. The authors present a retrospective analysis of 119 surgically treated femoral nerve lesions at intrapelvic and thigh levels seen at the Louisiana State University Health Sciences Center. Methods. Femoral nerve lesions treated between 1967 and 2000, (89 traumatic injuries and 30 tumors and cystic lesions) were evaluated for injury mechanisms, resulting lesions, surgical management, and postoperative functional outcomes by using retrospective chart reviews. The most common injury mechanism was iatrogenic (52 cases), which occurred after hernia and hip operations (10 each), followed by arterial bypass and gynecological procedures (eight each), angiography (seven), abdominal surgery (five), appendectomy (two), a laparoscopy, and a lumbar sympathectomy. Other injury mechanisms included hip or pelvic fractures (19), gunshot wounds (10), and lacerations (eight). The 30 femoral nerve tumors and cystic lesions consisted of neurofibromas (16), schwannomas (nine), ganglionic cysts (two), neurogenic sarcomas (two), and a leiomyosarcoma. Forty-four patients underwent neurolysis. Some had recordable nerve action potentials (NAPs) across their lesions in continuity, despite severe distal loss. Others with recordable NAPs had mild loss, but also experienced a pain problem, which was helped in some by neurolysis. In 36 patients, in whom repairs were performed using long sural grafts for mostly proximal pelvic-level injuries, recovery of useful function occurred. Eight of nine thigh-level suture repairs led to improvement to good functional levels. Most of the tumors and cystic lesions were resected, with preservation of preoperative function. Conclusions. The majority of femoral nerve injuries resulted in lesions in continuity, and intraoperative NAP recordings were essential in evaluating axonal regeneration across these lesions. Despite severe and frequently proximal injury levels requiring repairs with long grafts, femoral nerve lesion repairs resulted in good functional recovery.