Summary

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

Introduction

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

Materials And Methods

A non-randomized, prospective, controlled clinical trial was conducted. The FNB and ACB groups comprised 41 and 40 patients, respectively. Thirty minutes prior to surgery under general anesthesia, the patients received an ultrasound-guided LFCN block with FNB or ACB. The numerical rating scale (NRS) score was recorded 30 min and 4, 8, 12, 24, 48, and 72 h after surgery. These measures were compared between the FNB and ACB groups at each time point using the Wilcoxon rank-sum test. The administration and use of analgesic suppositories were also assessed. Factors affecting pain relief (NRS<2) were evaluated, including the block type, age, sex, body mass index (BMI), and suppository use. Significant factors predicting pain relief were determined using the Cox proportional hazard regression model.

Results

No significant difference was found in suppository use between the groups. 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: 1.77; 95% confidence interval: 1.05-2.89; p=0.03) after controlling age, sex, BMI, and suppository use.

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.