Postoperative Meralgia Paresthetica after Posterior Spine Surgery: Incidence, Risk Factors, and Clinical Outcomes

Study Design. A prospective study on postoperative meralgia paresthetica after posterior thoracolumbar spine surgery on the Relton-Hall frame. Objectives. To assess the incidence of postoperative lateral femoral cutaneous nerve (LFCN) neuralgia and to investigate its risk factors and clinical outcomes. Summary of Background Data. Postoperative meralgia paresthetica is a common complication of posterior thoracolumbar spine surgery. The injury mechanism is external compression to the LFCN near the anterior superior iliac spine in the prone position. Methods. A total of 252 patients were examined for signs of meralgia paresthetica before and after surgery. Patients with a LFCN injury were followed regularly until sensory impairment resolved. Several possible contributing factors were assessed to evaluate the correlations. Results. Postoperative meralgia paresthetica was experienced by 60 patients (23.8%). Patients with an LFCN injury had a significantly greater body mass index (23.6 vs. 22.4 kg/m2) and a longer surgical time (3.7 vs. 3.2 hours). Overweight/obese patients had a significantly greater incidence (odds ratio, 1.83; 95% confidence interval, 1.02-3.29). Patients operated for degenerative spinal disorders also had a significantly higher incidence of LFCN injury (odds ratio, 2.81 ; 95% confidence interval, 1.53-5.13). Recovery took 10.5 days on average (range, 2 days to 2 months). Thirty-two patients (53 %) recovered completely within the first week and every patient recovered within 2 months. Conclusion. Postoperative meralgia paresthetica is a common but benign complication of posterior thoracolumbar spine surgery. Degenerative spinal disorders, overweight/obesity, and longer surgical time are factors related to a higher incidence of LFCN injury. The clinical outcome is always excellent, and complete recovery can be expected within 2 months