Optimizing Postoperative Pain Management in Total Knee Arthroplasty With Preoperative Methadone: A Prospective, Randomized Study.

Abstract

Total knee arthroplasty (TKA) can result in major postoperative pain. Studies have shown that preoperative methadone administration can be effective in reducing pain and opioid requirements in spine surgery. Purpose of this study was to determine if a single dose of preoperative methadone can reduce postoperative opioid requirements while achieving effective pain control following primary TKA. In this prospective study, patients were randomized to either receive preoperative dose of oxycodone (10 mg) or methadone (10 mg). Postoperative analgesia was converted to morphine milligram equivalents (MME) before calculation of the daily MME use and 2-week average. There were 149 patients who consented and met the inclusion criteria: 74 in the methadone group and 75 in the oxycodone group. Data were collected via electronic medical record and a patient-reported daily opioid consumption datasheet was documented continuously for a 2-week period following the index TKA. The methadone group used significantly fewer opioids (in MME) on postoperative days (PODs) zero through four (POD zero, P = 0.002; POD one, P = 0.009; POD two, P = 0.025; POD three, P = 0.002; and POD four, P = 0.029) with an average of 122.4 MME compared to 164.3 MME in the control group, a 26% reduction in opioid consumption. Visual analog scale pain score was not significant between the groups at any time points. Mean total MME over the initial 2-week postoperative period for the methadone group was less than the oxycodone group (275.3 versus 314.7, P = 0.22). There were no adverse opioid-related reactions in either group. This study demonstrated the effectiveness and safety of a single preoperative dose of methadone (10 mg) in primary TKA in reducing postoperative opioid usage while maintaining a similar or better level of pain control when compared to a standard pain control regimen.