A new robotically assisted technique can improve outcomes of total knee arthroplasty comparing to an imageless navigation system.

Abstract

Robotic assisted total knee arthroplasty (RTKA) has shown improved knee alignment and reduced radiographic outliers. However, there remains debate on functional outcomes and patient-reported outcomes (PROMs). This study compares the 1-year clinical outcomes of a new imageless robotically assisted technique (ROSA Knee System, Zimmer Biomet, Warsaw, IN) with an imageless navigated procedure (NTKA, iAssist Knee, Zimmer, Warsaw, IN). The study is a retrospective analysis of prospectively collected data that compared the functional outcomes and PROMs of 50 imageless RTKA with 47 imageless NTKA at 1-year follow-up. Baseline characteristics, intraoperative and postoperative information were collected including complications, revisions, Knee Society Score (KSS), Knee injury and Osteoarthritis Outcome Score (KOOS) score, and Forgotten Joint Score (FJS-12). Radiographic analysis of preoperative and postoperative images evaluating hip-knee-ankle (HKA) angle was performed. There was no difference regarding baseline characteristics between the groups. Mean operative time was significantly longer in the RTKA group (122min vs. 97min; p < 0.0001). Significant differences were reported for the "Pain" (85 [RTKA] vs 79.1 [NTKA]; p = 0.0283) subsection of the KOOS score. In addition, RTKA was associated with higher maximum range of motion (119.4° vs. 107.1°; p < 0.0001) and better mean improvement of the arc of motion by 11.67° (23.02° vs. 11.36°; p < 0.0001). No significant differences were noted for other subsections of KOOS, KSS, FJS-12, complications, or limb alignment at 1-year follow-up. Imageless RTKA was associated with longer surgical time, better pain perception and improved ROM at 12-month follow-up compared with NTKA. No significant differences were reported on other PROMs, complication rates and radiographic outcomes. III.