Patients Undergoing Revision Total Knee Arthroplasty for Stiffness Have Similar Perioperative Pain Scores and Postoperative Opioid Consumption Compared to Patients Undergoing Revisions for Other Aseptic Indications.

Abstract

Patients undergoing revision TKA (rTKA) for stiffness have inferior clinical outcomes compared to other aseptic indications, but whether they have higher or more prolonged opioid consumption is unclear. This study compared (1) postoperative pain scores, (2) 90-day postoperative opioid use, and (3) duration of opioid use in patients undergoing rTKA for stiffness versus aseptic indications. This study included 337 patients who underwent rTKA for stiffness (n = 162, 48.1%) or for aseptic loosening or instability (control; n = 175, 51.9%) from 2018 to 2022. Patients completed a phone survey at 10, 28, and 90 days postoperatively to assess pain and opioid use, and chart review was performed to collect demographic, pain, and Morphine Milligram Equivalents (MME) data. Stiffness and control rTKA groups were compared for each outcome using Chi-square or Student's t-tests. Stiff rTKA patients had significantly higher rates of preoperative opioid usage than control patients (15.4 versus 5.7%, P = 0.003). Overall rates of opioid use were 84, 49, and 12% at 10, 28, and 90 days postoperative and did not differ between groups at any timepoint (P > 0.05). Both groups had similar pain scores at six weeks postoperatively (2.75 versus 2.81; P = 0.6), similar total MME (695.2 versus 785; P = 0.7), similar inpatient hourly MME consumption (1.66 versus 1.70; P = 0.7), and a similar number of opioid refills (0.55 versus 0.76; P = 0.2). Patients undergoing rTKA for stiffness had similar MME, opioid refills, time to opioid discontinuation, and pain scores as control patients despite higher preoperative opioid use. Given the lower 90-day survey response rate in the stiffness cohort, these findings should be interpreted with caution, as similarity in 90-day use was not supported under the worst-case non-responder scenario. This information should help guide patient counseling and pain management expectations after rTKA for stiffness.