Summary

This study compares short-term patient-reported outcomes (PROMs) following Total Knee Arthroplasty (TKA) using robotic-assisted and computer-navigated systems, revealing no significant difference between the two robotic systems (CORI – Smith & Nephew, USA; ROSA – Zimmer Biomet, France), and indicating better patient satisfaction and normality with computer navigation over the use of robotics.

Abstract

Introduction

In recent years, robotic surgery has expanded greatly and the use of semi-active robotic-assisted Total Knee Arthroplasty (TKA) continues to gain popularity with aims to improve patient outcomes. The benefits of computer navigation in TKA are well established over a longer time frame, and although early studies have demonstrated some benefits of robotic systems, there is limited evidence on the clinical outcomes and patient reported outcomes (PROMs) compared to computer navigation. To further justify the use of these modalities, it is important to compare outcomes between each robotic system, as well as compare with the more established computer navigation.
Objectives: This study had two primary aims: to conduct a comparative analysis of short-term PROMs following TKA performed with robotic-assistance or computer navigation, and to compare PROMs following TKA performed with either ROSA (Zimmer Biomet, France) or CORI (Smith & Nephew, USA) robotic systems.

Methods

This was a retrospective analysis of prospectively collected data of patients who underwent primary TKA for osteoarthritis. Surgeries were performed by two surgeons, utilising either semi-active robotic-assisted (CORI or ROSA), or computer navigated surgical systems (Stryker Precision or Orthosoft), between December 2021 and April 2023. At 12 months follow-up, PROMs for each group were collected using several scoring systems: Oxford Knee Score (OKS), Forgotten Joint Score (FJS), VR-12 scores, pain (VAS) and patient satisfaction outcomes.

Results

A total of 398 patients were recruited: 211 underwent robotic-assisted TKA (CORI: n=104; ROSA: n=107), and 187 with computer navigation alone. There were no significant differences in patient characteristics and pre-operative PROMs between groups at baseline. At 12 months, the post-op patient satisfaction (91.5 vs 86.5, p=0.005), normality (84.4 vs 78.7, p=0.02) and VAS (12.6 vs 17.5, p=0.03) were significantly better in the combined navigation group than the combined robotic-assisted group (CORI and ROSA). In addition, post-op VR 12 mental scores in navigation group were slightly better (54.8 vs 52.7, p=0.04). There was a drop in delta VR 12 mental scores in the robotic group (-3.49 vs -7.33, p=0.04), but there was no significant difference between the delta scores of FJS and OKS observed in the robotic-assisted and navigation comparison. Between the CORI and ROSA groups, the CORI group demonstrated a significantly better post-operative patient normality score (82.3 vs 74.8, p=0.04), however, no other significant difference was seen between the two robotic-assisted systems.

Conclusion

The development of further technology to improve TKA outcomes continues to expand with the increased adoption of many robotic-assisted systems. This study demonstrated no significant difference in outcomes between the two robotic systems, and whilst there was benefit seen in patient satisfaction with the use of navigation over robotics, there was no difference in the validated PROMS. The findings show no clear short-term benefits for well-established navigation surgeons to change to a robotic technique, although clearly further investigations will be useful to clarify this question.