Research Abstract
Background: Postoperative pain control after knee arthroscopy improves recovery and alleviates opioid-related complications. The adductor canal block is considered a promising method for providing effective analgesia with minimal motor impairment, but the most effective site for injection has yet to be determined. Aim: This randomized controlled trial evaluated the effectiveness of ultrasound-guided proximal versus distal ACB compared with standard care without nerve block for pain management after knee arthroscopy. Patients and Methods: Seventy-five patients undergoing elective knee arthroscopy were randomly divided into three groups, each consisting of 25 individuals: Proximal ACB, Distal ACB, and Control. The ACB groups received 20 mL of 0.375% bupivacaine administered at their respective locations under ultrasound guidance. Assessments were conducted over 24 hours to evaluate postoperative pain intensity (VAS scores), opioid use (tramadol), motor function (Bromage scale), and recovery indicators. Statistical analysis was conducted using ANOVA and Chi-square tests, with a threshold of P < 0.05 for significance. Results: The cumulative tramadol consumption was the lowest in the Proximal ACB group, with a consumption of 95.2 ± 18.6 milligrams, followed by the Distal ACB group at 108.4 ± 19.5 milligrams and the Control group at 165.8 ± 25.4 milligrams, with a highly significant difference of P < 0.001. Pain scores based on the Visual Analogue Scale were significantly lower for both ACB groups compared with the Control group, with a highly significant difference of P < 0.001, and the Proximal ACB group demonstrated the best pain relief. Motor function was maintained in all groups, with a Bromage score of 0 observed in 100% of patients at 24 hours. The proximal ACB group exhibited a significantly longer delay in initial pain medication requests, with a mean time of 385 ± 112 minutes, compared withwind distal ACB (298 ± 95 minutes) and the Control group (145 ± 65 minutes, P < 0.001). Both groups had higher patient satisfaction ratings and experienced fewer opioid-related side effects, such as nausea and vomiting. Conclusion: Proximal ultrasound-guided ACB was associated with better postoperative pain relief, lower opioid usage, and faster recovery than distal ACB and typical treatment protocols. The motor-sparing characteristics of this technique make it a valuable component in multimodal pain management strategies for knee arthroscopic procedures.