Liposomal bupivacaine surgical site injection for decrease of narcotic use in hip fractures: a pilot multicenter randomized trial

Objectives: To conduct a pilot randomized control trial evaluating the effectiveness of liposomal bupivacaine to potentially inform a larger trial for effect size and feasibility. Design: Double-Blinded Multicenter Randomized Control Trial. Setting: Level I trauma centers. Patients/Participants: Patients older than 55 years with isolated fragility hip fractures undergoing surgery. Intervention: Liposomal bupivacaine (TX) or placebo injection of saline (P). Main Outcome Measurements: Morphine milliequivalents at 24, 48, and 72 hours postoperatively. Visual analog scale pain scores, Confusion Assessment Method scores, delirium episodes, and surgical/medical complications were all used as secondary outcomes. Results: = 0.37. There was no significant difference in opiate use and visual analog scale scores any time point. There was no difference in Confusion Assessment Method scores or episodes of confusion/delirium nor surgical or medical complications. A 72-hour time point for data collection was not feasible, whereas 48 hours was, with 89% of data points collected. The sample size required for a superiority trial to detect a 20% difference in opioid use would require 518 patients. Conclusions: We were unable to demonstrate a clinical difference between liposomal bupivacaine and placebo in narcotic use, pain scores, or postoperative delirium in geriatric fragility fractures. It is possible that there may be a small effect size that we were unable to detect, and a larger study may demonstrate that. However, given the unlikely large improvement in pain, expense of the medication, and technique dependent nature, a smaller difference does not warrant a larger trial nor uniform administration. Level of Evidence: Level 1. Clinical Trial Registration Number: NCT03289858.