IS TOURNIQUET USE ASSOCIATED WITH A DIFFERENCE IN PATIENT-REPORTED OUTCOMES FOLLOWING TOTAL KNEE ARTHROPLASTY? A MULTICENTRE COMPARISON

Total knee arthroplasty (TKA) is one of the most commonly performed elective procedures in North America. It is expected that the annual volume of TKAs will continue to grow as indications expand and the population ages. While there have been advancements made in patient optimization, surgical technique and implant design there continues to be a subset of patients that remain unhappy with their outcome following TKA. The use of a tourniquet intraoperatively has been a contentious issue and thought to potentially contribute to this phenomenon. With patient reported outcome measures (PROMs) being routinely collected as a tool to assess quality, we sought to identify whether tourniquet use is associated with a difference in PROMs post-operatively. As part of the PEPPER Trial, a database of over 15,000 patients was used to identify patients who underwent primary TKA with or without a tourniquet between December 2016 to November 2022. Preoperative to postoperative changes in PROMs were assessed at 1, 3 and 6 months postoperatively. PROMs collection consisted of the Knee Osteoarthritis Outcome Score Jr. (KOOS-Jr), Patient-Reported Outcomes Measurement Information System Physical Health Summary (PROMIS-PH) and the Numerical Pain Rating Scale (NPRS). Mean Clinically Important Differences (MCID) were calculated for each PROM based on established criteria. Secondary outcome measures collected consisted of complications, healthcare utilization, opioid consumption and operative time. Statistical analysis was performed comparing patient cohorts via χ² and t-tests. Multivariable regression analysis was performed to identify patient and surgical factors that influence PROMs. 5684 patients underwent elective TKA and met criteria for this analysis. 4865 (85.6%) underwent surgery with a tourniquet (YT) and 818 (14.4%) underwent surgery without a tourniquet (NT). 28 sites across North America contributed patients to the study cohort. Patients who underwent TKA without a tourniquet were younger, less comorbid and more likely to receive a cementless component. There was no difference in operative time, length of stay or discharge destination. There was similarly no difference between NT and YT at any time point with respect to KOOS-JR, PROMIS-PH and NPRS. There was no difference in opioid consumption, wound related complications and readmissions postoperatively. The proportion of patients reaching the MCID for each given PROM increased with each time interval. However, between 24-53% of patients had not reached the MCID target by 6 months. In a large patient cohort there was no difference in PROMs, opioid consumption, healthcare utilization or complications in patients undergoing TKA with or without a tourniquet. With a large proportion of patients not meeting MCID targets by 6 months, the recovery from TKA continues to be evidently a long process. This further reinforces the need for appropriate patient education and expectation setting prior to TKA.