Liposomal bupivacaine versus ropivacaine for surgical site infiltration in lumbar fusion: a prospective randomized controlled trial.

Abstract

INTRODUCTION: Effective postoperative pain control after lumbar spine surgery remains challenging, and excessive opioid use is associated with adverse outcomes. Evidence comparing liposomal bupivacaine (LB) with conventional long-acting local anesthetics in spine surgery is limited. PATIENTS AND METHODS: In this single-center, prospective, randomized, patient- and outcome assessor-blinded trial, adult undergoing one- or two-level posterior lumbar decompression and fusion were assigned (1:1) to surgical site infiltration with either LB (266&#x2009;mg) plus 25&#x2009;mg plain bupivacaine (LB group) or ropivacaine (R group). The primary outcome was 72&#x2009;h cumulative opioid consumption (morphine milligram equivalents, MME). Secondary outcomes included time-profile opioid consumption, pain scores, rescue analgesia, safety, and functional recovery. RESULTS: A total of 202 patients were included in the modified intention-to-treat analysis. Cumulative MME within 72&#x2009;h was significantly lower in the LB group compared with the R group [43.0 (37.0, 58.0) mg vs. 58.0 (46.0, 73.0) mg], corresponding to a 22% relative reduction (GMR 0.78, 95% CI 0.71-0.85; p&#x2009;<&#x2009;0.001). The reduction was most pronounced during 8-24&#x2009;h and 24-48&#x2009;h postoperatively. Overall pain scores at rest and with movement, as well as 72-h pain AUC, were lower in the LB group. No significant between-group differences were observed in rescue analgesia, adverse events and functional recovery. CONCLUSION: In patients undergoing one- or two-level posterior lumbar decompression and fusion, surgical site infiltration with an LB-based combined regimen, compared with ropivacaine monotherapy, reduced 72-h opioid consumption and cumulative postoperative pain burden without an observed increase in adverse events or impairment of early functional recovery.