Trial results for the ROSA Total Knee Post Market Study EMEA, which included patients with Rheumatoid Arthritis, were posted on ClinicalTrials.gov on 2026-01-21. The study enrolled a total of 252 participants.
Background
Rheumatoid Arthritis is a chronic inflammatory disorder that can affect joints, leading to pain, swelling, and potential joint damage, including in the knees. For patients experiencing severe knee pain and functional limitations due to conditions like Rheumatoid Arthritis, Chronic Osteoarthritis, or Avascular Necrosis of the Femoral Condyle, total knee replacement is a common surgical intervention. This study aimed to compare the surgical workflow efficiency and patient-reported functional outcomes between robotic-assisted total knee instrumentation and conventional instrumentation, providing insights into the practical application of these different surgical approaches.
Trial design
This completed, non-phase (NA) clinical study enrolled 252 participants. The trial included patients with conditions such as Knee Pain, Chronic Osteoarthritis, Avascular Necrosis of the Femoral Condyle, Moderate Varus, Valgus or Flexion Deformities, and Rheumatoid Arthritis. The primary objective of the study was to evaluate the accuracy of implant alignment for ROSA Total Knee robotic instrumentation compared to conventional instrumentation. The study compared the use of the ROSA Total Knee Robotic system against conventional instrumentation, utilizing Persona, Nexgen, and Vanguard product families.
Key results
The trial reported key measurements for operative workflow efficiency and patient function outcomes:
- Operative Workflow Efficiency (minutes):
- For the Robotic group, a mean of 161.6 minutes (Standard Deviation 30.9) was observed.
- For the Conventional group, a mean of 138.8 minutes (Standard Deviation 27.9) was observed.
- In another measurement for the Robotic group, a mean of 91.5 minutes (Standard Deviation 21.1) was observed.
- For the Conventional group, a mean of 77.5 minutes (Standard Deviation 20.3) was observed.
- Oxford Knee Score (OKS) (score on a scale):
- For the Robotic group, a mean score of 21.5 (Standard Deviation 7.5) was observed.
- For the Conventional group, a mean score of 20.6 (Standard Deviation 6.8) was observed.
- In another measurement for the Robotic group, a mean score of 30.5 (Standard Deviation 7.1) was observed.
- For the Conventional group, a mean score of 29.0 (Standard Deviation 7.8) was observed.
- A further measurement for the Robotic group showed a mean score of 36.3 (Standard Deviation 8.0).
- For the Conventional group, a mean score of 35.0 (Standard Deviation 9.6) was observed.
- Finally, for the Robotic group, a mean score of 38.5 (Standard Deviation 8.9) was observed.
- For the Conventional group, a mean score of 38.2 (Standard Deviation 9.2) was observed.
What this means
The posted results indicate differences in operative workflow efficiency and patient-reported outcomes between robotic-assisted and conventional total knee replacement procedures. The robotic system was associated with longer operative times, with mean workflow efficiency measurements of 161.6 minutes and 91.5 minutes compared to 138.8 minutes and 77.5 minutes for conventional instrumentation, respectively. Conversely, Oxford Knee Scores, which assess patient pain and function, were generally slightly higher in the robotic group across multiple measurements (e.g., 38.5 vs 38.2, 36.3 vs 35.0). These findings suggest a potential trade-off between increased operative time with robotic assistance and marginally improved patient-reported functional scores. For patients with Rheumatoid Arthritis and other conditions requiring total knee replacement, these data contribute to the understanding of practical considerations when choosing between surgical approaches, though further analysis would be needed to determine statistical significance of these differences.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for the study NCT04338893, titled 'ROSA Total Knee Post Market Study EMEA', were posted on 2026-01-21 on clinicaltrials.gov.