Prospective Randomized Trial Comparing Femoral Nerve Block With Intraoperative Local Anesthetic Injection of Liposomal Bupivacaine in Total Knee Arthroplasty

373 patients scheduled for total knee arthroplasty were randomized to a postoperative analgesia regimen featuring either intraoperative periarticular infiltration analgesia with liposomal bupviacaine, or a preoperative femoral nerve block. Patients were assessed for analgesic and functional measures at 12-hour intervals following surgery, as well as at 6-week, 3-month, and 1-year follow-up. Outcomes demonstrated significant differences in favour of the FNB group for pain scores and knee range of motion at 12 and 24 hours after surgery, and a significant differences in favour of the LB PAI group in the ability to perform the straight leg raise test at 12 hours. The differences between groups in these outcome measures at subsequent follow-up points were not significant. In addition, no significant differences between groups were observed in pain medication consumption for the first 84 hours, walking distance for the first 48 hours, or the incidence of falls.