Liposomal Bupivacaine vs Ropivacaine for Adductor Canal Blocks in Total Knee Arthroplasty: A Prospective Randomized Trial

The purpose of this study is to determine the benefit of the analgesic liposomal bupivacaine compared to ropivacaine, by assessing pain and joint stiffness, and total oral opioid consumption by milligram morphine equivalent (MME) after total knee arthroplasty.Patients were randomized to receive either the study drug (liposomal bupivacaine admixed with bupivacaine) or the control drug (ropivacaine) in an adductor canal block. Only the anesthesiologist performing the block was aware of which arm of the study the patient was randomized to. MME, pain, Knee injury and Osteoarthritis Outcome Score Joint Replacement, and overall benefit of analgesia scores were recorded 24, 48, and 72 hours post-surgery either face-to-face or via telephone depending on patient discharge status.One hundred patients were enrolled into the study and analyzed: 54 in the control group and 46 in the experimental group. Primary outcomes measured were pain as a numerical rating scale, MME, and length of stay in hours. Secondary outcomes were joint pain and stiffness recorded as Knee injury and Osteoarthritis Outcome Score Joint Replacement outcome and overall benefit of analgesia score. No statistically significant between-group differences were observed for any measured outcome.We did not find any supporting evidence that liposomal bupivacaine yields increased pain relief following total knee arthroplasty compared to the control drug, ropivacaine.