Comparison of the 4-in-1 Block Technique with Femoral and Adductor Canal Blocks in Arthroscopic Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

Objectives: This study aimed to assess how effective the 4-in-1 block technique is for pain control around the time of surgery in patients undergoing anterior cruciate ligament reconstruction (ACLR). The technique performance was compared with that of femoral nerve block (FNB) and adductor canal block (ACB). Methods: In this single-blind randomized trial, patients scheduled for ACLR under general anesthesia were assigned randomly to one of three groups: 4-in-1 block, FNB, or ACB. All blocks were subjected to ultrasound guidance with 20 mL of 0.25% bupivacaine approximately 45 minutes before surgery. We recorded intraoperative remifentanil use, postoperative opioid consumption, and pain scores measured by the numerical rating scale (NRS). Results: A total of 60 patients were equally divided among the groups. Compared with the ACB group, the 4-in-1 block group used, on average, 0.8 mg fewer opioids in the first 24 hours $ost-operatively (90% confidence interval [CI], −5.61--4.01). Compared with that in the FNB group, opioid use was 2.8 mg greater (90% CI, −1.48--7.08). In both cases, the 90% one-sided CIs remained within the preset margin of noninferiority of 10 mg. NRS revealed that the 4-in-1 block was not inferior to the ACB at any measured time point and was not inferior to the FNB at 4, 8, or 24 hours after surgery. Discussion: The effectiveness of the 4-in-1 block for controlling pain was similar to that of both FNB and ACB in patients undergoing ACLR. These findings suggest that this method could be considered a practical alternative to traditional nerve block methods in the perioperative management of ACLR. Trial registration: ClinicalTrials.gov identifier: NCT05643040. Registered 23 November 2022. Retrospectively registered.