Ultrasound-guided adductor canal block is superior to femoral nerve block for early postoperative pain relief after single-bundle anterior cruciate ligament reconstruction with hamstring autograft

Abstract

Purpose: This study aimed to compare the combination of a lateral femoral cutaneous nerve (LFCN) block with a femoral nerve block (FNB) and an adductor canal block (ACB) for postoperative pain control in patients undergoing anterior cruciate ligament (ACL) reconstruction with hamstring autograft.

Methods: A non-randomized, prospective, controlled clinical trial was conducted. The FNB and ACB groups consisted of 41 and 40 patients, respectively. Thirty minutes prior to surgery, the patients received an ultrasound-guided LFCN block either with FNB or ACB. The following values were recorded and compared between the two groups: duration of surgery, pain management during surgery (including total amount of fentanyl administered), and numerical rating scale (NRS) scores at 30 min and 4, 8, 12, 24, 48, and 72 h after surgery. Factors affecting pain relief (NRS < 2) were evaluated, including block type, total amount of fentanyl administered, duration of surgery, age, sex, body mass index, and postoperative suppository use. Significant factors predicting pain relief were determined using the Cox proportional hazard regression model.

Results: There were no significant differences in pain management during the surgery. Pain scores were significantly lower in the ACB group at 30 min, 4 h, 24 h, and 48 h after surgery. The Cox proportional hazard regression model identified ACB as a significant factor for pain relief (hazard ratio: 1.88; 95% confidence interval: 1.12-3.13; p = 0.018).

Conclusion: The combination of ACB with LFCN block during ACL reconstruction significantly reduced pain in the early postoperative period compared to FNB with LFCN block.

Keywords: Adductor canal block; Anterior cruciate ligament reconstruction; Femoral nerve block; Lateral femoral cutaneous nerve block; Pain management.