Pain Control After Total Hip Arthroplasty: A Randomized Controlled Trial Determining Efficacy of Fascia Iliaca Compartment Blocks in the Immediate Postoperative Period

Background The purpose of this randomized controlled trial is to identify if a fascia iliaca block reduces postoperative pain and narcotic consumption and improves early functional outcomes in primary total hip arthroplasty (THA) performed through the mini-posterior approach. Methods Patients were recruited from September 2017 to September 2019. Eligible patients received a primary THA using a mini-posterior approach with epidural anesthesia. Postoperatively, patients were randomized to receive a fascia iliaca compartment block or a placebo block. Numeric Rating Scale pain scores, narcotic consumption, and functional outcomes were recorded at regular intervals postoperatively. Results Upon study completion, 122 patients were available for final analysis. There was no difference in the average pain scores at any time interval between the placebo and block groups during the first 24 hours (P = .21-.99). There was no difference in the morphine equivalents consumed between the groups during any time interval postoperatively (P = .06-.95). Functional testing showed no difference in regards to distance walked during the first therapy session (67.1 vs 68.3 ft., P = .92) and timed-up-and-go testing (63.7 vs 66.3 seconds, P = .86). There was an increased incidence of quadriceps weakness in the block group (22% vs 0%, P = .004) requiring alterations in therapy protocols. Conclusion This randomized trial shows that a fascia iliaca compartment block does not improve functional performance and does not decrease pain levels or narcotic usage after mini-posterior THA, but does increase the risk of quadriceps weakness postoperatively. Based on these results we do not recommend routine fascia iliaca compartment blocks after THA performed with the mini-posterior approach.