A Comparative Study of Ultrasound-Guided Continuous Adductor Canal Block With Ultrasound-Guided Continuous Femoral Nerve Block in Unilateral Total Knee Arthroplasty for Limb Mobilization and Analgesic Efficacy

Background Total knee joint replacement surgery is associated with severe postoperative pain and is amenable to regional anesthesia techniques for pain control. Femoral nerve block (FNB) provides effective analgesia after total knee arthroplasty (TKA) but has been associated with delayed ambulation due to quadriceps muscle weakness. Adductor canal block (ACB) may be a promising alternative, with less effect on the quadriceps muscle and comparable analgesic efficacy. We evaluated the effectiveness, safety, and patient satisfaction of continuous ACB augmented with infiltration between the popliteal artery and capsule of the knee (iPACK) block and compared them with those of continuous FNB amplified with iPACK block in preventing postoperative pain among patients undergoing unilateral total knee replacement (TKR) surgeries. Methodology According to a computer-generated sequence from September 2019 to June 2020, 50 American Society of Anesthesiologists grades I-III patients aged between 35 and 75 years who underwent unilateral TKR surgery were randomized into two equal groups, namely, ACB and FNB. The Timed Up and Go (TUG) and 10-minute walk tests were used to detect early ambulation (impact on quadriceps muscle). The secondary goal was to evaluate and compare opioid consumption and analgesic efficacy between the groups measured using a numeric rating scale (NRS). The demographic characteristics, technical difficulty, efficiency, safety, and comfort were compared between the two groups. Results During the postoperative period, patients in the ACB group could perform all TUG tests significantly faster than those in the FNB group. The mean get-up time in the ACB group was 39.08 +/- 5.53 seconds, whereas that in the FNB group was 44.92 +/- 7.10 seconds (p < 0.01). The 3-m walk time was 123.16 +/- 15.90 seconds in the ACB group and 134.68 +/- 13.13 seconds in the FNB group (p < 0.01). The 10-m walk time was 221.24 +/- 18.82 seconds in the ACB group and 245.24 +/- 21.68 seconds in the FNB group (p < 0.001). No significant difference was observed in NRS scores between the groups after the first 24 hours. The number of opioids available for consumption in both groups was equivalent. Conclusions ACB when augmented with an iPACK block is a good alternative to FNB for unilateral TKR surgeries. ACB may promote early ambulation without a reduction in analgesia when compared with FNB.