Local Infiltration Analgesia With Liposomal Bupivacaine Improves Pain Scores and Reduces Opioid Use After Total Knee Arthroplasty: Results of a Randomized Controlled Trial.

Abstract

Local infiltration analgesia (LIA) with liposomal bupivacaine (LB) in patients undergoing total knee arthroplasty (TKA) has yielded mixed results. The PILLAR study, which was designed to minimize limitations associated with previous studies, compared the effects of LIA with or without LB on pain scores, opioid consumption, including proportion of opioid-free patients, time to first opioid rescue, and safety after primary unilateral TKA. Patients (N = 140) were randomized to LIA with LB 266 mg/20 mL (admixed with bupivacaine HCl 0.5%, 20 mL) or LIA with bupivacaine HCl 0.5%, 20 mL. Standardized infiltration techniques and a standardized multimodal pain management protocol were used. The coprimary efficacy endpoints were area under the curve (AUC) of visual analog scale pain intensity scores 12-48 hours (AUC_12-48) postsurgery and total opioid consumption 0-48 hours postsurgery. Mean AUC_12-48 of visual analog scale pain intensity score was 180.8 with LB and 209.3 without LB (least squares [LS] mean treatment difference -26.88, P = .0381). LS mean total opioid consumption 0-48 hours postsurgery was 18.7 mg with and 84.9 mg without LB (LS ratio 0.220, P = .0048). Significant differences in favor of LB were observed for the percentage of opioid-free patients (P < .01) and time to first opioid rescue (P = .0230). Treatments were similarly well tolerated. This study provides data on LIA with LB administered using optimal techniques specific to TKA. In this setting, LIA with LB significantly improved postsurgical pain, opioid consumption, and time to first opioid rescue, with more opioid-free patients and no unexpected safety concerns.