Study Summary

One hundred forty-nine patients undergoing primary total knee arthroplasty (TKA) were randomized to receive either preoperative intravenous methadone 10 mg or preoperative oral immediate-release oxycodone 10 mg. The primary outcomes of interest were daily opioid consumption measured in morphine milligram equivalents (MME), total opioid use over 2 weeks, and daily visual analog scale (VAS) pain scores. Secondary outcomes included length of stay, discharge disposition, narcotic refill rates at 2 and 6 weeks, Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR), range of motion, and complications. Outcomes were assessed daily for 2 weeks and through 6 weeks postoperatively. Overall, the results of the study revealed that patients receiving methadone used significantly fewer opioids during postoperative days 0 to 4 while maintaining similar pain scores compared with oxycodone. No increase in adverse events was observed. These findings suggest that a single preoperative dose of methadone is a safe and effective strategy for reducing early postoperative opioid requirements following primary TKA.