Comparison of Postoperative Pain Management Between Saphenous Nerve Block and High-Volume Proximal Adductor Canal Block for Arthroscopic Knee Surgery

Abstract

Background: Lower limb surgeries are typically accompanied by severe postoperative pain, and managing such pain is of great importance. Inadequate pain management can lead to serious complications such as myocardial ischemia and impaired pulmonary function. To manage pain, local anesthetic techniques have been introduced as effective methods. One of these techniques is the high-volume proximal adductor canal block (HI-PAC), in the distal third of the medial thigh, which directly targets the femoral nerve and indirectly the sciatic nerve. Methods: In this double-blind study, patients aged 30 to 70 years with American Society of Anesthesiologists (ASA) physical status I and II who underwent anterior cruciate ligament (ACL) reconstruction were divided into two groups. Both groups received general anaesthesia using the same method. The control group received an ultrasound-guided saphenous nerve block in the proximal third of the anteromedial thigh with 0.2% ropivacaine (15 mL), while the case group received a HI-PAC in the distal third of the thigh with 0.1% ropivacaine (30 mL). Pain intensity and analgesic effectiveness were evaluated at predetermined time points (baseline, 0.5, 2, 4, 6, and 12 hours post-block). Pain severity was assessed using the Numeric Rating Scale (NRS), and agitation was measured with the Ramsay Sedation Score. Data were analyzed using appropriate statistical tests via SPSS version 26. Results: A total of 50 patients participated: 24 in the case group (HI-PAC block) and 26 in the control group (saphenous nerve block). In terms of pain scores (NRS), the initial pain score was 9.20 in group A and 9 in group S. Pain intensity decreased significantly over time in both groups. At 0.5, 2, 4, 6, and 12 hours after the block, the average NRS score was 4.01 in group A and 4.18 in group S. Conclusions: The mean opioid consumption and level of agitation were similar in both groups. Multivariate analysis indicated that both nerve block techniques were equally effective in reducing acute postoperative pain, and the type of block did not have a statistically significant effect on pain severity.