Efficacy of Anterior Quadratus Lumborum Block and Pain After Total Hip Arthroplasty: A Randomized Controlled Trial

Background: Anterior quadratus lumborum block (AQLB) is one of the compartment blocks and has recently attracted attention as a new method of analgesia for postoperative hip surgery analgesia. This study aimed to compare the analgesic efficacy of AQLB in patients undergoing primary total hip arthroplasty (THA).Methods: There were 120 patients undergoing primary THA under general anesthesia randomly allocated to receive a femoral nerve block (FNB) or an AQLB. The primary outcome was total morphine consumption over the initial 24-hour postoperative period. Secondary outcomes included the pain score evaluation while at rest and during active and passive motion over the 2 days following surgery and the manual muscle testing of the quadriceps femoris. The numerical rating scale (NRS) score was used for evaluating the postoperative pain score.Results: There were no significant differences between the 2 groups concerning morphine consumption within 24 hours after surgery (P = .72). The NRS score at rest and passive motion were similar at all-time points (P > .05). However, there was a statistically significant difference in pain reported during the active motion for the FNB group compared to the AQLB (P = .04). No significant differences were found between the 2 groups concerning muscle weakness incidence.Conclusion: Both AQLB and FNB demonstrated adequate efficacy for postoperative analgesia at rest in THA. However, based on our study, whether AQLB is inferior or noninferior to FNB as an analgesic method for THA was inconclusive.(c) 2023 Elsevier Inc. All rights reserved.