Intraoperative local infiltration analgesia for early analgesia after total hip arthroplasty: a randomized, double-blind, placebo-controlled trial.

BACKGROUND AND OBJECTIVES High-volume local infiltration analgesia (LIA) is widely applied as part of a multimodal pain management strategy in total hip arthroplasty (THA). However, methodological problems hinder the exact interpretation of previous trials, and the evidence for LIA in THA remains to be clarified. Therefore, we evaluated whether intraoperative high-volume LIA, in addition to a multimodal oral analgesic regimen, would further reduce acute postoperative pain after THA. METHODS Patients scheduled for unilateral, primary THA under spinal anesthesia were included in this randomized, double-blind, placebo-controlled trial receiving high-volume (150 mL) wound infiltration with ropivacaine 0.2% with epinephrine (10 μg/mL) or saline 0.9%. A multimodal oral analgesic regimen consisting of slow-release acetaminophen 2 g, celecoxib 400 mg, and gabapentin 600 mg was instituted preoperatively. Rescue analgesic consisted of oral oxycodone. Pain was assessed repeatedly the first 8 hrs after surgery using the 100-mm visual analog scale. The primary end point was pain during walking (5 m) 8 hrs after surgery. Secondary end points were pain at rest, pain on 45 degrees of passive flexion of the hip with the leg straight, and cumulative consumption of oxycodone. RESULTS A total of 120 patients were included. Pain during walking (median [interquartile range] [95% confidence interval]) was low in the ropivacaine versus the placebo group (20 [14-38] [0-93] vs 22 [10-40] [0-83]) and did not differ significantly (P = 0.71). Consumption of rescue oxycodone (5 mg [0-10 mg] [0-24 mg] vs 10 mg [0-15 mg] [0-29 mg]) did not differ (P = 0.45). CONCLUSIONS Intraoperative high-volume LIA with ropivacaine 0.2% provided no additional reduction in acute pain after THA when combined with a multimodal oral analgesic regimen consisting of acetaminophen, celecoxib, and gabapentin and is therefore not recommended.