Quadratus lumborum block versus femoral nerve block in total hip arthroplasty: a randomized clinical trial

The innervation of the hip joint is complex, and multimodal analgesia enables optimal management of postoperative pain and early mobilization. This includes administration of regional anesthesia. Numerous blocks for total hip arthroplasty (THA) have been documented in the literature and recently the quadratus lumborum block (QLB) has been reported for use in hip replacement surgery. In the present randomized controlled trial, a comparison was made between QLB and femoral nerve block (FNB) in patients undergoing THA. We selected morphine consumption in the first 24 hours after surgery as the primary outcome. We hypothesized that QLB would obtain better results than FNB. We conducted a prospective, controlled, randomized, simple-blind trial at the University Hospital of Reims (France). Patients undergoing primary THA were included and were allocated to receive either QLB or FNB. Blinded observers recorded cumulative morphine consumption at 24 hours, pain scores at 1, 2, 6, 12 and 24 hours, use of other analgesics, and length of stay. There were 76 patients in the QLB group and 81 in the FNB group. There was no statistical difference in cumulative morphine consumption at 24h between both groups (14,6 +/- 12 mg vs 13,5 +/- 10,8 mg, p = 0.35, in the QLB and the FNB groups respectively). No clinically significant intergroup differences were found in terms of postoperative pain scores and length of hospital stay. In THA, QLB is not associated with a significant change in postoperative morphine consumption in our study when compared with FNB. ClinicatTrials.gov identifier: NCT: NCT03666260; Retrospectively registered, October 10, 2018.