Intra-articular ropivacaine 0.75% and bupivacaine 0.50% for analgesia after arthroscopic knee surgery: a randomized prospective study

Purpose: Intra-articular administration of local anesthetic solution provides analgesia after arthroscopic knee surgery. Bupivacaine is considered the gold standard local anesthetic in this indication, but ropivacaine, which is less toxic than bupivacaine, can consequently be administered in higher doses, potentially increasing the duration of analgesia. We compared the analgesic effect of intraarticular injection of ropivacaine 225 mg and bupivacaine 150 mg in patients undergoing arthroscopic surgery. Type of Study: Double-blind, randomized prospective clinical study. Methods: The study included 45 patients scheduled for knee meniscus repair under arthroscopy, who were allocated randomly into 3 groups to receive, intra-articularly, 30 mL of isotonic saline, bupivacaine 0.5 %, or ropivacaine 0.75 % solutions at the end of surgery. Postoperatively, pain was measured using a visual analog scale (VAS) at rest and on mobilization. Propacetamol was given when patients complained of pain. Results: VAS scores at rest. and on mobilization were higher in the saline group compared with the ropivacaine group (P = .006 and P = .01, respectively). No difference in VAS scores was documented between bupivacaine and the saline groups. The median delay between the intra-articular administration and propacetamol administration was shorter in the saline group (15 minutes; range, 15 to 120 minutes) compared with the ropivacaine group (240 minutes; range 15 to 720 minutes) but no difference was documented between the bupivacaine group (30 minutes; range, 15 to 360 minutes) and the other 2 groups. Conclusions: This level I study documents that intra-articular ropivacaine 0.75 % provides better analgesia than bupivacaine 0.5 % after knee arthroscopic surgery. Level of Evidence: Level I.