title: The effect of local anaesthetic wound infiltration on chronic pain after lower limb joint replacement: a protocol for a double-blind randomised controlled trial.
abstract: BACKGROUND
  For the majority of patients with osteoarthritis (OA), joint replacement is a successful intervention for relieving chronic joint pain. However, between 10-30% of patients continue to experience chronic pain after joint replacement. Evidence suggests that a risk factor for chronic pain after joint replacement is the severity of acute post-operative pain. The aim of this randomised controlled trial (RCT) is to determine if intra-operative local anaesthetic wound infiltration additional to a standard anaesthesia regimen can reduce the severity of joint pain at 12-months after total knee replacement (TKR) and total hip replacement (THR) for OA.
  
  
  METHODS
  300 TKR patients and 300 THR patients are being recruited into this single-centre double-blind RCT. Participants are recruited before surgery and randomised to either the standard care group or the intervention group. Participants and outcome assessors are blind to treatment allocation throughout the study. The intervention consists of an intra-operative local anaesthetic wound infiltration, consisting of 60 mls of 0.25% bupivacaine with 1 in 200,000 adrenaline. Participants are assessed on the first 5 days post-operative, and then at 3-months, 6-months and 12-months. The primary outcome is the WOMAC Pain Scale, a validated measure of joint pain at 12-months. Secondary outcomes include pain severity during the in-patient stay, post-operative nausea and vomiting, satisfaction with pain relief, length of hospital stay, joint pain and disability, pain sensitivity, complications and cost-effectiveness. A nested qualitative study within the RCT will examine the acceptability and feasibility of the intervention for both patients and healthcare professionals.
  
  
  CONCLUSIONS
  Large-scale RCTs assessing the effectiveness of a surgical intervention are uncommon, particularly in orthopaedics. The results from this trial will inform evidence-based recommendations for both short-term and long-term pain management after lower limb joint replacement. If a local anaesthetic wound infiltration is found to be an effective and cost-effective intervention, implementation into clinical practice could improve long-term pain outcomes for patients undergoing lower limb joint replacement.
  
  
  BACKGROUND
  Current Controlled Trials ISRCTN96095682.
authors.affiliation: Musculoskeletal Research Unit, School of Clinical Sciences, University of Bristol, Avon Orthopaedic Centre, Southmead Hospital, Bristol, BS10 5NB, UK. V.Wylde@bristol.ac.uk
authors.forename: Vikki
authors.initials: V
authors.lastname: Wylde
authors.forename: Rachael
authors.initials: R
authors.lastname: Gooberman-Hill
authors.forename: Jeremy
authors.initials: J
authors.lastname: Horwood
authors.forename: Andrew
authors.initials: A
authors.lastname: Beswick
authors.forename: Sian
authors.initials: S
authors.lastname: Noble
authors.forename: Sara
authors.initials: S
authors.lastname: Brookes
authors.forename: Alison J
authors.initials: AJ
authors.lastname: Smith
authors.forename: Mark
authors.initials: M
authors.lastname: Pyke
authors.forename: Paul
authors.initials: P
authors.lastname: Dieppe
authors.forename: Ashley W
authors.initials: AW
authors.lastname: Blom
mesh_terms: D000779:Anesthetics, Local / Q000191:economics / Q000627:therapeutic use*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D002045:Bupivacaine / Q000191:economics / Q000627:therapeutic use; D002908:Chronic Disease; D003362:Cost-Benefit Analysis; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006801:Humans; D007430:Intraoperative Care; D008137:Longitudinal Studies; D010149:Postoperative Pain / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control*; D017060:Patient Satisfaction; D015995:Prevalence; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D000779:Anesthetics, Local; D002045:Bupivacaine