Efficacy of Femoral Nerve Block Compared to Adductor Canal Block for Post Operative Pain Management After Total Knee Arthroplasty

Background: After total knee arthroplasty, regional anaesthetic methods such as femoral nerve and adductor canal blocks are frequently used to ease the pain. Objective: To assess how femoral nerve and adductor canal blocks affect post-operative mobility, healing time, and pain management following total knee arthroplasty. Methodology: From October 8, 2023, to September 25, 2024, a tertiary care hospital hosted this cross-sectional study. We randomly assigned 160 patients receiving unilateral primary total knee replacement to either the adductor canal or femoral nerve block (80 in each group). Before surgery, each group had their nerve block. Postoperative pain was measured at 6, 12, 18, and 24 hours using the numeric rating scale. Mobility on postoperative days 1–7 and the time until straight leg raise were recovery markers. Results: Age (femoral nerve block: 65.4±8.3 years; ACB: 64.8±7.9 years), gender distribution, body mass index, and ASA physical state did not significantly differ across groups. At every time point, the femoral nerve block group's pain scores were significantly lower: at 6 hours, this score was 3.8±1.2, compared to the adductor canal block's 4.2±1.3 (p=0.04). These tendencies continued at later evaluations (p<0.03). About 35% of the femoral nerve block group and 67.5% of the ACB group, respectively, attained straight leg raise greater than 30° on Day 1 (p<0.001). By Day 7, 93.75% of the femoral nerve block group and 100% of the ACB group had pain-free straight leg raise (p=0.05). According to multiple regression analysis, femoral nerve block was substantially linked to quicker recovery and lower pain scores (B=-0.5, p=0.001). Conclusion: After total knee arthroplasty, femoral nerve block provides better postoperative pain management and a faster recovery than adductor canal block, although adductor canal block allows for earlier leg mobilization and improves straight leg raise recovery.