Additive analgesic effect of intermittent adductor canal infusion to pericapsular injection after total knee arthroplasty: A randomized controlled trial

Introduction: A randomized controlled trial was conducted to evaluate whether the addition of intermittent adductor canal block (ACB) infusion to pericapsular injection (PCI) provides superior postoperative analgesia in total knee arthroplasty (TKA). Methodology: Patients undergoing unilateral TKA were randomized to receive either PCI alone or a combination of PCI and intermittent ACB for postoperative pain management. In patients undergoing bilateral TKA, one knee received PCI alone while the contralateral knee received PCI with ACB. The primary outcome was postoperative pain, assessed using the visual analog scale (VAS). Secondary outcomes included overall pain satisfaction, functional milestones, and opioid usage. Results: Data from 42 unilateral TKAs (20 PCI alone, 22 PCI + ACB) and 31 bilateral TKAs were analyzed. VAS scores were significantly lower in the PCI + ACB group in both unilateral (mean VAS 1.64 ± 0.58 vs. 2.15 ± 0.67) and bilateral (1.48 ± 0.62 vs. 2.35 ± 0.71) cohorts during the first 48 h postoperatively. In bilateral TKAs, the PCI + ACB knees demonstrated significantly better range of motion, higher satisfaction with pain control, and faster achievement of active straight leg raise (1.09 vs. 1.8 days). Time to ambulate 50 meters, Timed Up and Go (TUG test), and improved quadriceps strength also favored the PCI + ACB group, though not significantly. Morphine use and adverse effects were minimal in both groups. Conclusions: The addition of intermittent ACB to PCI significantly improves early postoperative analgesia and enhances functional recovery following TKA, compared to PCI alone.