Study Summary

This trial enrolled and evaluated 119 patients undergoing elective knee arthroplasty. Patients were randomized to receive an ultrasound-guided adductor canal block with either ropivacaine (Group R) or liposomal bupivacaine (Group B) prior to induction of general anesthesia. One patient withdrew after randomization, resulting in 119 patients included in the final analysis. The primary outcome of interest was postoperative pain intensity, assessed using visual analog scale scores (VAS) at rest and during movement at 2, 24, 48, and 72 hours postoperatively. Secondary outcomes included weighted area under the curve for VAS scores, patient-controlled intravenous analgesia presses between 12 and 48 hours, early functional recovery measures (pain-free knee bending angle and 10-second walking distance), quality of recovery, patient satisfaction, and adverse events. Outcomes were assessed over the first 72 hours postoperatively. Overall, the results of the study revealed that liposomal bupivacaine provided significantly lower pain scores and sustained analgesia up to 72 hours, with improved early functional recovery compared with ropivacaine.