[Comparative observation of analgesic efficacy between liposomal bupivacaine and "cocktail" therapy following artificial intelligence-assisted direct anterior approach total hip arthroplasty: A prospective randomized controlled study].

Abstract

Objective: To compare the analgesic efficacy and safety of liposomal bupivacaine (LB) versus ropivacaine for surgical incision local anesthesia after artificial intelligence (AI)-assisted direct anterior approach (DAA) total hip arthroplasty (THA).

Methods: A prospective randomized controlled study was conducted. A total of 120 patients who underwent AI-assisted DAA-THA between March 2024 and January 2025 were enrolled and randomly assigned to the LB group ( n=60) or the "cocktail" group ( n=60). Patients in the LB group received an intraoperative injection of LB 266 mg (diluted to 100 mL) around the incision, whereas those in the "cocktail" group received a mixture of ropivacaine 200 mg, compound betamethasone 1 mL, and epinephrine 0.5 mg (diluted to 100 mL). Resting and active visual analogue scale (VAS) scores were recorded at 6, 12, 24, 36, 48, 60, and 72 hours and at 2 and 4 weeks postoperatively. Changes in Pain Catastrophizing Scale (PCS) score, Harris hip score, and hip flexion and abduction range of motion at 4 weeks postoperatively relative to preoperative values were assessed. In addition, operation time, incision length, total postoperative oral morphine consumption, time to first ambulation, length of hospital stay, and complications within 72 hours after surgery were recorded and compared between the two groups.

Results: There was no significant difference between the two groups in incision length, time to first ambulation, length of hospital stay, or total postoperative oral morphine consumption ( P>0.05). Operation time was significantly longer in the LB group than in the "cocktail" group ( P<0.05). All patients were followed up for 6 months postoperatively. Both resting and active VAS scores decreased over time in the two groups ( P<0.05). Intergroup comparison showed that resting and active VAS scores at 60 and 72 hours postoperatively were significantly lower in the LB group than in the "cocktail" group ( P<0.05), whereas no significant difference was observed at other time points ( P>0.05). There was no significant difference between the two groups in the changes in PCS score, Harris Hip Score, or hip range of motion at 4 weeks postoperatively ( P>0.05). In the LB group, nausea and vomiting occurred in 3 cases, significant blood glucose fluctuations in 2 cases, superficial incision infection in 1 case, and local hematoma in 1 case; the corresponding numbers in the "cocktail" group were 5, 4, 0, and 1 case, respectively. No significant difference was observed between the two groups in the incidence of these complications ( P>0.05). No local allergic reactions, deep vein thrombosis, significant blood pressure fluctuations, deep incision infection, skin necrosis, or pulmonary embolism occurred in either group. At last follow-up, satisfaction rates for analgesic efficacy and hip function both exceeded 90% in the two groups, with no significant difference between groups ( P>0.05).

Conclusion: In AI-assisted DAA-THA, local infiltration anesthesia with LB provides analgesic efficacy comparable to that of the "cocktail" therapy during the early postoperative period (within 48 hours). Although VAS scores were slightly lower in the LB group at 60-72 hours postoperatively, the difference was small and the clinical benefit was limited. No significant difference was observed between the two groups in opioid consumption, complication rates, PCS scores, or postoperative functional recovery. In the context of AI-assisted DAA-THA, the clinical advantage of LB over the conventional "cocktail" therapy appears limited.