Efficacy of acetaminophen for pain management following total joint arthroplasty: Systematic review and network meta-analysis.

BACKGROUND: Acetaminophen is widely used in multimodal analgesia after total joint arthroplasty (TJA), but the comparative effects of different regimens remain uncertain. METHODS: PubMed, Embase, Cochrane Library, and Web of Science were searched through September 22, 2025 for randomized controlled trials evaluating acetaminophen or propacetamol regimens after total hip or knee arthroplasty. A Bayesian network meta-analysis was performed using R 4.4.0 and JAGS 4.3.1. Outcomes included pain scores at 6, 12, and 24 h and 24 h supplemental analgesic consumption, expressed as standardized mean differences (SMDs) with 95% credible intervals (CrIs). RESULTS: Fifteen RCTs including 1986 patients and six interventions were analyzed. For 24 h supplemental analgesic consumption, multiple-dose intravenous propacetamol and multiple-dose intravenous acetaminophen ranked highest (SUCRA 90.37% and 86.94%) and were superior to control (SMD 0.49 [0.18, 0.81] and 0.45 [0.27, 0.63], respectively). For 24 h pain, multiple oral and multiple intravenous acetaminophen reduced scores versus control (SMD 0.25 [0.05, 0.45] and 0.18 [0.005, 0.35], respectively). No significant differences were found at 12 h. At 6 h, multiple-dose intravenous propacetamol showed the largest effect (SMD 0.96 [0.49, 1.42]). CONCLUSIONS: Acetaminophen-based regimens may provide modest postoperative analgesic and opioid-sparing benefits after TJA, particularly with selected multiple-dose intravenous protocols. However, no single regimen was consistently superior across outcomes and time points, and SUCRA rankings should be interpreted alongside effect estimates and clinical feasibility.