Ultrasound-guided suprainguinal fascia iliaca compartment block and early postoperative analgesia after total hip arthroplasty: a randomised controlled trial

Background: Hip replacement surgery can be painful; postoperative analgesia is crucial for comfort and to facilitate recovery. Regional anaesthesia can reduce pain and postoperative opioid requirements. The role of ultrasound-guided suprainguinal fascia iliaca block for analgesia after elective total hip arthroplasty is not well defined. This randomised trial evaluated its analgesic efficacy. Methods: Consenting participants (134) scheduled for elective primary total hip arthroplasty under spinal anaesthesia were randomly allocated to receive ultrasound-guided fascia iliaca block with ropivacaine 0.5% or sham block with saline. The primary outcome was opioid consumption in the first 24 h after surgery. Additional outcomes included pain scores at 4, 8, 12, and 16 h, opioid-related side-effects (nausea, vomiting, pruritis), ability to perform physiotherapy on the first postoperative day, and physiotherapist-assessed quadriceps weakness. Results: There were no significant differences in 24-h opioid consumption (block vs sham block, mean difference - 3.2 mg oral morphine equivalent, 95% confidence interval - 15.3 to 8.1 mg oral morphine equivalent, P = 0.55) or any other prespecified outcomes. Conclusions: In patients undergoing primary total hip arthroplasty, ultrasound-guided suprainguinal fascia iliaca block with ropivacaine did not confer a significant opioid-sparing effect compared with sham block. There were no differences in other secondary outcomes including pain scores, opioid-related side-effects, or ability to perform physiotherapy on the first postoperative day.