title: Postoperative meralgia paresthetica after posterior spine surgery: incidence, risk factors, and clinical outcomes.
abstract: METHODS
  A prospective study on postoperative meralgia paresthetica after posterior thoracolumbar spine surgery on the Relton-Hall frame.
  
  
  OBJECTIVE
  To assess the incidence of postoperative lateral femoral cutaneous nerve (LFCN) neuralgia and to investigate its risk factors and clinical outcomes.
  
  
  BACKGROUND
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Orthopedics, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
authors.forename: Shu-Hua
authors.initials: SH
authors.lastname: Yang
authors.forename: Chang-Chin
authors.initials: CC
authors.lastname: Wu
authors.forename: Po-Quang
authors.initials: PQ
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009408:Nerve Compression Syndromes / Q000150:complications*; D009765:Obesity / Q000150:complications; D019637:Orthopedic Procedures / Q000009:adverse effects*; D050177:Overweight; D010292:Paresthesia / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D010523:Peripheral Nervous System Diseases / Q000150:complications*; D011446:Prospective Studies; D020127:Recovery of Function; D012307:Risk Factors; D012867:Skin / Q000294:innervation*; D013122:Spinal Diseases / Q000150:complications; D013131:Spine / Q000601:surgery*; D013848:Thigh; D013997:Time Factors