title: Postoperative epidural analgesia compared with intraoperative periarticular injection for pain control following total knee arthroplasty under spinal anesthesia: a randomized controlled trial.
abstract: BACKGROUND
  Although epidural analgesia has been used for postoperative pain control after total knee arthroplasty, its usefulness is being reevaluated because of possible adverse effects. Recent studies have proven the efficacy of periarticular analgesic injection and its low prevalence of adverse effects. The present study compares the clinical efficacies of epidural analgesia and periarticular injection after total knee arthroplasty.
  
  
  METHODS
  This is a prospective, single-center, randomized controlled trial involving patients scheduled for unilateral total knee arthroplasty. One hundred and eleven patients were randomly assigned to periarticular injection or epidural analgesia groups. All patients were managed with spinal anesthesia. The surgical technique and postoperative medication protocol were identical in both groups. The primary outcome was postoperative pain at rest, quantified as the area under the curve of the scores on a visual analog pain scale to seventy-two hours postoperatively. The Student t test and chi-square test were used to compare the data between groups.
  
  
  RESULTS
  In the intention-to-treat analysis, the periarticular injection group had a significantly lower area under the curve for pain score at rest (788.0 versus 1065.9; p = 0.0059). In the periarticular injection group, the mean knee flexion angle was small but significantly better at postoperative day 1 (64.2° versus 54.6°; p = 0.0072) and postoperative day 2 (70.3° versus 64.6°; p = 0.021) than in the epidural analgesia group. The incidence of nausea at postoperative day 1 was significantly lower in the periarticular injection group (4.0% versus 44.3%; p < 0.0001). Transient peroneal nerve palsy was frequently seen in the periarticular injection group (12.0% versus 1.6%; p = 0.026).
  
  
  CONCLUSIONS
  Compared with epidural analgesia, periarticular injection offers better postoperative pain relief, earlier recovery of knee flexion angle, and lower incidence of nausea. Care should be taken to avoid transient peroneal nerve palsy when using periarticular injection.
  
  
  METHODS
  Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: Department of Orthopaedic Surgery, Nekoyama Miyao Hospital, 14-7 Konan, Chuo-ku, Niigata, Niigata, 950-1151 Japan. E-mail address for S. Tsukada: s8058@nms.ac.jp.
authors.forename: Sachiyuki
authors.initials: S
authors.lastname: Tsukada
authors.affiliation: Department of Orthopaedic Surgery, Nekoyama Miyao Hospital, 14-7 Konan, Chuo-ku, Niigata, Niigata, 950-1151 Japan. E-mail address for S. Tsukada: s8058@nms.ac.jp.
authors.forename: Motohiro
authors.initials: M
authors.lastname: Wakui
authors.affiliation: Department of Orthopaedic Surgery, Kawaguchi Kogyo General Hospital, 1-18-15 Aoki, Kawaguchi, Saitama, 332-0031, Japan.
authors.forename: Akiho
authors.initials: A
authors.lastname: Hoshino
mesh_terms: D000368:Aged; D015360:Analgesia, Epidural / Q000379:methods*; D000701:Analgesics, Opioid / Q000008:administration & dosage* / Q000009:adverse effects; D000775:Anesthesia, Spinal / Q000379:methods; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D016001:Confidence Intervals; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007270:Injections, Intra-Articular / Q000009:adverse effects / Q000379:methods; D007430:Intraoperative Care / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000187:drug effects; D010149:Postoperative Pain / Q000188:drug therapy* / Q000517:prevention & control; D017060:Patient Satisfaction / Q000706:statistics & numerical data; D011182:Postoperative Care / Q000379:methods; D011446:Prospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome
chemical_list: D000701:Analgesics, Opioid