Comparison of Continuous Adductor Canal Block with Single Shot Adductor Canal Block and IPACK Block for Postoperative Analgesia in Total Knee Arthroplasty – A Randomized Controlled Trial

Abstract Background: Effective postoperative pain control after total knee arthroplasty (TKA) remains a clinical challenge. Regional anaesthesia techniques, particularly adductor canal block (ACB) and interspace between the popliteal artery and capsule of the knee (IPACK) block, are increasingly being used to provide opioid-sparing analgesia with preserved quadriceps strength.Aim: To compare the efficacy and safety of continuous ACB with single-shot ACB plus IPACK block in patients undergoing unilateral TKA. Methods: Fifty-two ASA I–II patients aged 40–70 years were randomized into two groups (n=26 each). Group A received continuous ACB with 0.5% ropivacaine (20 ml bolus followed by 5 ml/hr infusion for 24 hours). Group B received single-shot ACB (0.5% ropivacaine 20 ml + dexmedetomidine 0.5 mcg/kg) plus IPACK block (0.5% ropivacaine 20 ml + dexmedetomidine 0.5 mcg/kg). Primary outcome was VAS pain scores. Secondary outcomes included opioid consumption, time to first rescue analgesia, ambulation distance, quadriceps strength, and complications. Results: Group A showed significantly lower VAS scores at 6, 12, and 24 hr (p<0.05), required less fentanyl (42 ± 8 mcg vs. 62 ± 10 mcg, p=0.001), and had longer time to first rescue analgesia (10.5 ± 2.1 hr vs. 6.4 ± 1.8 hr, p=0.001). Ambulation at 24 hr was greater in Group A (54.2 ± 9.1 m vs. 44.7 ± 8.6 m, p=0.02). Quadriceps strength was preserved in both groups. Complications were minimal. Conclusion: Continuous ACB provides superior analgesia, reduces opioid use, and facilitates early mobilization compared to single-shot ACB with IPACK in TKA.