COMPARISON OF EXISTING AND NEW TOTAL KNEE ARTHROPLASTY IMPLANT SYSTEMS FROM THE SAME MANUFACTURER: A PROSPECTIVE, MULTICENTRE STUDY

Introduction New implants for total knee arthroplasty (TKA) are frequently introduced with the promise of improved performance. Infrequently there is accompanying data to document relative performance. The goal of this study was to evaluate the outcomes of an implant widely used for decades (Existing TKA), compared to a new implant (New TKA) from the same manufacturer. Methods From October 2011-March 2015, 19 sites prospectively enrolled and implanted 752 Subjects with Existing TKA. Between November 2012 and May 2015, 23 sites (18 sites had enrolled Existing TKAs), implanted 1131 Subjects with the New TKA. Demographics were similar between groups. Subjects were seen preoperatively, <1-year, 1-year, and 2-years to collect patient reported outcome measures (PROMs), radiographs and any complications. PROMs consisted of Knee Injury and Osteoarthritis Outcome Score (KOOS) (permits WOMAC scoring), Oxford Knee Score (OKS), Patient's Knee Implant Performance (PKIP) and EQ5D-3L and a p-value of 0.01 was establishe...