title: Effect of lateral femoral cutaneous nerve-block on pain after total hip arthroplasty: a randomised, blinded, placebo-controlled trial.
abstract: BACKGROUND
  Total hip arthroplasty (THA) is a common procedure associated with moderate postoperative pain. No nerve block without loss of motor function has been documented for THA. We hypothesised that an ultrasound-guided lateral femoral cutaneous nerve (LFCN) block added to a multimodal postoperative pain regimen would reduce postoperative pain after THA.
  
  
  METHODS
  One hundred patients who had a THA by the posterior approach were evaluated in this randomised, placebo-controlled, blinded, parallel-group trial comparing an ultrasound-guided LFCN-block with either 8 ml of ropivacaine, 7.5 mg/ml, (Group Ropivacaine) or 8 ml of saline (Group Placebo) given postoperatively. Surgery was performed under spinal anaesthesia. The primary outcome was pain (measured on a Visual Analogue Scale (VAS)) 4 h post-blockade during 30° flexion of the hip. Secondary outcomes were pain at rest, pain during movement, oxycodone consumption (0-24 h), time to mobilisation, ability to mobilise, and length of stay. Patients, assessors and all staff involved with patient care were blinded to the intervention.
  
  
  RESULTS
  There was no difference in primary outcome between Group Ropivacaine and Group Placebo (VAS 27 mm vs. 31 mm, p = 0.41; difference -5 mm (95% CI: -15 mm - +5 mm). No differences in any of the secondary outcomes were observed. No adverse events, or harms, were observed during the trial.
  
  
  CONCLUSIONS
  Pain scores, opioid use, time to mobilisation, and length of stay were low in both Group Ropivacaine and Group Placebo. We found no added analgesic effect of a LFCN-block when combined with paracetamol and ibuprofen after THA by the posterior approach.
  
  
  BACKGROUND
  EudraCT: 2013-004501-12 (December 16th 2013).
authors.affiliation: Department of Anaesthesiology, Næstved Hospital, Ringstedgade 61, 4700, Næstved, Denmark. khty@regionsjaelland.dk.
authors.forename: Kasper H
authors.initials: KH
authors.lastname: Thybo
authors.affiliation: Department of Orthopaedic Surgery, Næstved Hospital, Ringstedgade 61, 4700, Næstved, Denmark.
authors.forename: Harald
authors.initials: H
authors.lastname: Schmidt
authors.affiliation: Department of Anaesthesiology, Næstved Hospital, Ringstedgade 61, 4700, Næstved, Denmark.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hägi-Pedersen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000779:Anesthetics, Local / Q000008:administration & dosage; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D001340:Autonomic Nerve Block / Q000379:methods*; D004311:Double-Blind Method; D005260:Female; D005267:Femoral Nerve; D006801:Humans; D008297:Male; D008875:Middle Aged; D059408:Pain Management / Q000379:methods*; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods; D010149:Postoperative Pain / Q000175:diagnosis* / Q000209:etiology / Q000517:prevention & control*; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local
keywords: Lateral femoral cutaneous nerve block; Peripheral nerve block; Postoperative analgesia; Total hip arthroplasty