1 Department of Clinical Medicine, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Københavns Universitet2 unknown3 Department of Clinical Medicine, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Københavns Universitet
a systematic review
Treatment of postoperative pain should rely on results from randomized controlled trials and meta-analyses of high scientific quality. The efficacy of a particular intervention may depend on the type of surgical procedure, which supports the reporting of "procedure-specific" interventions. The aim of this systematic review was to document the procedure-specific evidence for analgesic interventions after total hip arthroplasty (THA). This PRISMA-compliant and PROSPERO-registered review includes randomized placebo-controlled trials (RCTs) of medication-based analgesic interventions after THA. Endpoints were postoperative opioid consumption, pain scores (rest and during mobilization), adverse events, and length of hospital stay. Fifty-eight trials with 19 different interventions were retrieved. High risk of bias, substantial differences in assessment-tools and criteria for pain, irregular reporting of adverse events, considerable differences in supplemental analgesic consumption, and basic analgesic regimens generally characterized trials. Meta-analyses of non-steroidal anti-inflammatory drugs, local infiltration analgesia, intrathecal opioids, and lumbar plexus block provided a 24-hour intravenous morphine-sparing effect of 14.1 (95 % confidence interval: 8.0-20.2) mg, 7.5 (3.7-11.3) mg, 19.8 (14.9-24.7) mg, and 11.9 (6.4-17.3) mg, respectively. Non-steroidal anti-inflammatory drugs and lumbar plexus block were demonstrated to provide reductions in postoperative pain scores. Intrathecal opioids increased pruritus, and lumbar plexus block reduced nausea and pruritus. The GRADE-rated quality of evidence ranged from low to very low throughout the analyses. This review demonstrated, that some analgesic interventions may have the capacity to reduce mean opioid requirements and/or mean pain intensity compared with controls, but the available randomized placebo-controlled trials does not allow a designation of a "best proven intervention" for THA.