Opioid-sparing anesthesia based on opioid-free principles for early recovery after total knee arthroplasty: A randomized controlled trial.
OBJECTIVE To evaluate whether an opioid-sparing anesthesia strategy (OSA), based on opioid-free anesthesia (OFA), improves early postoperative recovery quality and optimizes functional outcomes after total knee arthroplasty (TKA), compared with conventional opioid-based anesthesia (OBA). DESIGN A randomized controlled trial with blinding of patients, surgeons, and outcome assessors. SETTING Single center, July 2025 to February 2026. PATIENTS 98 adult patients scheduled for elective unilateral TKA. INTERVENTION Patients were randomized to the OSA or OBA group. The OSA regimen used esketamine and dexmedetomidine as the primary analgesic backbone, whereas the OBA regimen was opioid-based. Both groups received preoperative femoral nerve block and were administered oxycodone at skin incision and closure. Postoperatively, both groups received the same multimodal analgesia and patient-controlled analgesia. MEASUREMENTS The primary outcome was the 24-h postoperative Quality of Recovery-15 (QoR-15) score. Secondary outcomes included 48-h QoR-15; Oxford Knee Score (OKS) and EQ-5D-3L at 1 and 3 months; high pain at 1 month and chronic postsurgical pain at 3 months. Exploratory outcomes included postoperative C-reactive protein (CRP), and postoperative nausea and vomiting (PONV), among others. RESULTS At 24 h postoperatively, QoR-15 was higher in the OSA group than in the OBA group (118.4 ± 11.5 vs 113.3 ± 12.2; adjusted difference 5.12, 95% CI 0.51-9.74; P = 0.029), and this advantage persisted at 48 h (adjusted difference 5.54, 95% CI 1.57-9.52; P = 0.007). The OSA group had a lower incidence of PONV (P = 0.025) and lower postoperative CRP levels (P = 0.001). At 1 month, OKS was higher in the OSA group (adjusted difference 2.31, 95% CI 0.34-4.27; P = 0.022), with no significant differences in other secondary outcomes. CONCLUSION In TKA, this OFA-based OSA strategy improved early postoperative QoR-15 scores. However, the QoR-15 difference did not reach the minimal clinically important difference, so its clinical relevance remains uncertain.