Many hospitals now advertise robotic-arm knee replacement as a more advanced option. It sounds better, and it often costs more. But does it actually give patients a better knee?
In August 2026, The Lancet published RACER-Knee, described by its authors as the largest blinded trial of its kind. It compared robotic-arm knee replacement with conventional surgery in routine hospital practice.
This article explains what the trial found, in plain language, and what to ask your surgeon.
Read More: Best Knee Replacement Surgery in Delhi
Key Findings from the Trial
- One year after surgery, patients in both groups reported almost the same “forgotten joint” score, so the robot gave no meaningful advantage on the main measure
- Other measures, including pain, walking, and the chance of a follow-up operation, were also similar
- The robotic operations took longer and cost more
- The authors say the robot’s better precision may become worthwhile only if future work shows it helps tailor surgery to each patient’s anatomy
How the Trial Was Conducted
- It was a pragmatic trial, meaning it tested surgery as delivered in everyday practice, not in ideal conditions
- It took place at ten hospitals in Great Britain, with 33 surgeons and 339 patients who had advanced knee arthritis
- Patients were randomly placed into a robotic group (using the Mako robotic-arm system) or a conventional-instruments group
- Patients and the staff assessing results did not know which surgery each person had
- The main outcome was the Forgotten Joint Score at 12 months. It measures how aware a person is of their artificial knee in daily life
What Did the Researchers Discover?
- Main result: the average score was 49.2 in the robotic group and 50.2 in the conventional group. The trial was designed to detect a 12-point difference, so this gap is not meaningful
- Other outcomes: Oxford Knee Score, quality of life, pain, and activity showed no meaningful differences at 3, 6, or 12 months
- Safety: patients had a similar likelihood of a follow-up operation
- Cost and time: robotic surgery took longer and was more expensive in this trial
- Earlier evidence: a smaller earlier trial of 100 patients also found no significant difference at 6 or 12 months, though earlier observational studies had hinted at better medium-term results with robotics
What This Means for Patients
- A robot is a tool. In this trial, it did not make the average patient’s knee feel better at one year
- If a hospital quotes a higher price for robotic surgery, it is fair to ask what benefit you are paying for
- Good to know:
- The trial tested one system (Mako) in the UK, so results may not apply to every robot or country
- It followed patients for 12 months. Long-term follow-up is ongoing, and durability of implants is a longer-term question
- Robotic surgery is not unsafe based on this trial. The finding is that it was not better on patient-reported results
- Surgeon experience, implant choice, and rehabilitation still matter a great deal
When to Speak With a Specialist
Consider discussing this with an orthopaedic surgeon if you:
- Have been advised knee replacement and are comparing robotic and conventional quotes
- Are unsure whether the extra cost of a robotic system is justified for your knee
- Want to know which approach the surgeon is most experienced in
- Want a second opinion before deciding on surgery
Future Research and Next Steps
- Long-term follow-up of the RACER-Knee patients is ongoing
- Researchers want to test whether robotics can help tailor the operation to each person’s anatomy
- Trials of other robotic systems, and of partial knee replacement, are still needed
Conclusion
For the average patient, RACER-Knee found no meaningful difference between robotic-arm and conventional knee replacement at one year, and the robot cost more. The practical takeaway: choose the surgeon and the implant plan first, and treat the robot as an optional tool, not a guarantee of a better knee.
How ConsultGrab Helps You
Choosing between knee replacement options can be confusing, especially when costs differ. ConsultGrab supports patients with:
- Understanding your case in detail
- Connecting you with orthopaedic surgeons for knee replacement consultation
- Clear explanations of treatment options and how they compare
- Support throughout the process, so you do not have to decide alone
Medical Disclaimer: This article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
Frequently Asked Questions (FAQs)
In the RACER-Knee trial, patients had similar results at 12 months on the main "forgotten joint" score and on pain, walking, and follow-up operations. Robotic surgery took longer and cost more. It was not shown to give better patient-reported outcomes.
RACER-Knee was a blinded, randomised trial published in The Lancet in 2026. It compared robotic-arm and conventional knee replacement at ten UK hospitals with 339 patients, and measured how aware patients were of their new knee after 12 months.
The authors and reports describe the robot as more precise. But in this trial, better precision did not translate into better patient-reported results at one year. Future research may show whether tailoring the operation to each person's anatomy changes that.
Not necessarily. Surgeon experience, implant choice, and rehabilitation matter a great deal. If a robotic option costs more, it is reasonable to ask your surgeon what specific benefit it offers for your knee.
Not necessarily. The trial tested one system, the Mako, in the UK, and followed patients for 12 months. Other systems, and longer-term outcomes, need their own trials. Long-term follow-up of these patients is ongoing.
Original Research Source
This article is based on findings from a scientific research study and related media reporting.
Primary Research: Robotic-arm-assisted versus conventional total knee replacement (RACER-Knee), The Lancet (2026)
Media Coverage: Medical Xpress · EurekAlert
The content has been independently rewritten, analyzed, and simplified for educational purposes to help patients and families better understand the research findings.
