Liposomal Bupivacaine Infiltration and Postoperative Pain Outcomes in Lumbar Fusion: A Prospective Randomized Controlled Trial.

Background: Postoperative pain after lumbar fusion may impair coughing and early mobilization. Whether liposomal bupivacaine provides better analgesia than ropivacaine infiltration in this setting remains unclear. Methods: In this single-center randomized controlled trial, 94 patients undergoing multi-segmental posterior lumbar fusion were randomized to LB+B or RH wound infiltration. Outcomes included resting and cough-induced pain scores, rescue opioid use, recovery and sleep quality, length of stay, and adverse events. Results: The prespecified primary endpoint (24-hour resting VAS) did not differ between groups. In baseline-adjusted longitudinal GEE models, neither the overall treatment effect nor the treatment-by-time interaction was statistically significant for resting or dynamic pain. Model-based estimates indicated only modest between-group differences, which were below commonly cited minimal clinically important difference thresholds. Rescue opioid use over 48 hours was similar between groups, and no differences were observed in rescue analgesia, recovery quality, sleep quality, length of stay, or adverse events. Conclusion: In this randomized trial, LB+B did not show a significant overall analgesic advantage over ropivacaine infiltration and was not associated with opioid-sparing or recovery benefits. Clinical Trial Identifier: The date of first registration in 19/07/2023 ChiCTR2300073714. https://www.chictr.org.cn/.