Liposomal bupivacaine versus continuous ropivacaine infusion in adductor canal block for total knee arthroplasty

Liu Chenglong; Wei Shanwen; Li Di; Zou Mingming; Ma Yanxia

doi:10.12307/2026.775

Abstract：BACKGROUND:Effective analgesia after total knee arthroplasty is crucial for rehabilitation,with adductor canal block being a commonly used method.Traditional single-injection local anesthetics provides limited analgesic duration,and continuous catheter infusion exhibits complexity and high cost. OBJECTIVE:To compare the efficacy and safety of a single injection of liposomal bupivacaine versus continuous catheter infusion of ropivacaine hydrochloride for adductor canal block analgesia after total knee arthroplasty. METHODS:Eighty patients undergoing primary unilateral total knee arthroplasty at Gaoyou People's Hospital from March 2024 to February 2025 were randomly assigned to two groups:the liposomal bupivacaine group and the continuous infusion group.The liposomal bupivacaine group received a single adductor canal block injection of 133 mg(10 mL)liposomal bupivacaine mixed with 5 mL of 0.75%ropivacaine hydrochloride postoperatively.The continuous infusion group received an adductor canal block catheter placed near the saphenous nerve,connected to an analgesic pump delivering 0.25%ropivacaine hydrochloride(loading dose:10 mL;infusion rate:6 mL/h).Analgesic efficacy was assessed by comparing pain scores at various time points postoperatively,postoperative analgesia-free duration,morphine rescue consumption,and postoperative walking distance in both groups.Safety was evaluated by monitoring complications.Additionally,procedural time,cost,patient satisfaction,and hospital stay were compared between the two groups. RESULTS AND CONCLUSION:(1)Pain scores at rest and during movement showed no significant differences between liposomal bupivacaine group and continuous infusion group at 6,12,24,48,and 72 hours postoperatively(P>0.05).The postoperative analgesia-free duration was 19 hours in the liposomal bupivacaine group and 22 hours in the continuous infusion group(P>0.05).(2)Within 72 hours postoperatively,the liposomal bupivacaine group required an average of 78.6 morphine rescue treatments,while the continuous infusion group required 80.5,without significant differences(P>0.05).(3)Procedural time was significantly shorter in the liposomal bupivacaine group(6.1±1.4 min)than in the continuous infusion group(20.3±1.2 min,P<0.05).(4)No differences were observed in patient satisfaction,hospital stay,or walking ability(P>0.05).(5)One case of quadriceps paralysis occurred in the continuous infusion group at 6 hours postoperatively but resolved spontaneously without further complications.Each patient in the liposomal bupivacaine group saved 132 RMB in analgesia-related costs.(6)It is concluded that within 72 hours after total knee arthroplasty,single-injection liposomal bupivacaine provided comparable analgesia to continuous ropivacaine infusion in terms of pain scores,postoperative analgesia-free duration,and morphine rescue requirements.Hospital stay,patient satisfaction,and functional recovery were similar.However,single-injection liposomal bupivacaine adductor canal block is more convenient,saves time,and reduces costs.