Efficacy and Safety of Liposomal Bupivacaine in Direct Anterior Approach Total Hip Arthroplasty: A Retrospective Cohort Study

Background:This retrospective observational analysis aimed to assess potential associations between liposomal bupivacaine (LB) and ropivacaine for local infiltration analgesia on early postoperative outcomes in patients undergoing direct anterior approach total hip arthroplasty (DAA-THA). Material/Methods:A total of 129 patients with femoral neck fracture or femoral head necrosis were enrolled (inclusion criteria: no preoperative infection, normal inflammation, complete data; exclusion criteria: anesthetic allergy, severe liver/kidney dysfunction, cognitive impairment).Patients were divided into an LB group (n=61) and ropivacaine group (n=68).Primary outcomes were resting and active visual analog scale (VAS) scores on postoperative days (POD) 1-3 and 7. Secondary outcomes included sleep quality score, adverse events, and inflammatory, liver/kidney function markers. Results:Baseline characteristics were comparable.LB group showed significantly lower resting and active VAS scores on POD 1-3 (all P<0.05), lower sleep quality scores on POD 1-2 (both P<0.001), and lower incidence of nausea/vomiting (4.92% vs 17.65%, P=0.024).No significant differences were found in 72-hour rescue opioid use, inflammatory markers, liver and kidney function, or other adverse events (all P>0.05). Conclusions:In this retrospective observational analysis of DAA-THA patients receiving standardized multimodal analgesia, LB-based local infiltration analgesia was associated with modest early pain reduction, potentially better shortterm sleep quality, and lower nausea/vomiting incidence, without increasing 72-hour rescue opioid use or laboratory safety risks.These findings are associative and exploratory; they do not establish causality or clinical superiority.Prospective, large-scale studies are needed to confirm these associations and evaluate long-term functional and economic outcomes.