title: Effect of local anaesthetic infiltration on chronic postsurgical pain after total hip and knee replacement: the APEX randomised controlled trials.
abstract: Total hip replacement (THR) and total knee replacement (TKR) are usually effective at relieving pain; however, 7% to 23% of patients experience chronic postsurgical pain. These trials aimed to investigate the effect of local anaesthetic wound infiltration on pain severity at 12 months after primary THR or TKR for osteoarthritis. Between November 2009 and February 2012, 322 patients listed for THR and 316 listed for TKR were recruited into a single-centre double-blind randomised controlled trial. Participants were randomly assigned (1:1) to receive local anaesthetic infiltration and standard care or standard care alone. Participants and outcomes assessors were masked to group allocation. The primary outcome was pain severity on the WOMAC Pain Scale at 12 months after surgery. Analyses were conducted using intention-to-treat and per-protocol approaches. In the hip trial, patients in the intervention group had significantly less pain at 12 months postoperative than patients in the standard care group (differences in means: 4.74; 95% confidence interval [CI]: 0.95-8.54; P = 0.015), although the difference was not clinically significant. Post hoc analysis found that patients in the intervention group were more likely to have none to moderate pain than severe pain at 12 months than those in the standard care group (odds ratio: 10.19; 95% CI: 2.10-49.55; P = 0.004). In the knee trial, there was no strong evidence that the intervention influenced pain severity at 12 months postoperative (difference in means: 3.83; 95% CI: -0.83 to 8.49; P = 0.107). In conclusion, routine use of infiltration could be beneficial in improving long-term pain relief for some patients after THR.
authors: Musculoskeletal Research Unit, School of Clinical Sciences, University of Bristol, Bristol, United Kingdom School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom North Bristol NHS Trust, Brunel Building, Bristol, United Kingdom Medical School, University of Exeter, Exeter, United Kingdom.
authors: Vikki
authors: V
authors: Wylde
authors: Erik
authors: E
authors: Lenguerrand
authors: Rachael
authors: R
authors: Gooberman-Hill
authors: Andrew D
authors: AD
authors: Beswick
authors: Elsa
authors: E
authors: Marques
authors: Sian
authors: S
authors: Noble
authors: Jeremy
authors: J
authors: Horwood
authors: Mark
authors: M
authors: Pyke
authors: Paul
authors: P
authors: Dieppe
authors: Ashley W
authors: AW
authors: Blom
mesh_terms: D000368:Aged; D000772:Anesthesia, Local / Q000379:methods*; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D059350:Chronic Pain / Q000188:drug therapy / Q000209:etiology; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000601:surgery; D010149:Postoperative Pain / Q000188:drug therapy* / Q000209:etiology*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome