Comparison of adductor canal block with topical anesthesia for postoperative analgesia in patients undergoing arthroscopic knee surgery

Abstract

Objective To compare adductor canal block(ACB)with topical anesthesia for postoperative analgesia in the patients undergoing arthroscopic knee surgery. Methods Sixty patients of both sexes, aged 18-64 yr, with body mass index of 18-30 kg/m2, of American Society of Anesthesiologists physical status ⅠorⅡ, scheduled for elective arthroscopic meniscectomy, were divided into 2 groups (n=30 each) using a random number table: ACB group and topical anesthesia group(TA group). In group ACB, 0.2% ropivacaine 20 ml was injected into the adductor canal under the guidance of ultrasound at 30 min before operation to perform ACB.In group TA, 0.25% ropivacaine 20 ml was injected into the articular cavity at 5 min before the end of operation.The development of effective analgesia (VAS scores ≤4)and weakened quadriceps femoris muscle strength(muscle strength 0-2 grade, post-operative muscle strength was assessed by using manual muscle testing), related complications(local anesthetic intoxication, bleeding at the puncture site and hematoma) and occurrence of postoperative nausea, vomiting and delayed emergence were recorded. Results Compared with group TA, the rate of effective analgesia within 12 h after surgery was significantly increased (P 0.05). Local anesthetic intoxication, bleeding at the puncture site, hematoma or delayed emergence was not observed in the two groups. Conclusion ACB produces better efficacy for postoperative analgesia than topical anesthesia in the patients undergoing arthroscopic knee surgery. Key words: Nerve block; Anesthesia, local; Arthroscopy; Pain, postoperative