A large UK clinical trial has found that robotic assistance in knee replacement surgery does not lead to better patient outcomes during the first year, despite enabling surgeons to perform the procedure with greater precision.
The RACER-Knee trial, coordinated by the University of Warwick and University Hospitals Coventry and Warwickshire NHS Trust, is the largest randomized trial of robotic-assisted knee replacement. Published in The Lancet, the study compared conventional total knee replacement with surgery using the Stryker Mako robotic system.
The trial involved 339 patients, 33 surgeons and 10 hospitals across the UK. After 12 months, patients in both groups reported similar levels of recovery, mobility and pain. There was also no significant difference in the Forgotten Joint Score, which measures how noticeable an artificial knee feels during everyday activities.
Robotic surgery did provide greater accuracy in positioning the implant. However, this did not translate into better pain relief, walking ability or a reduced need for further surgery. Serious complications were also similar between the two groups.
“Technology such as this could really help the care we give for patients, but for robotic-assisted knee replacements, there is still work to do before we see benefits such as less pain or better movement,” said Professor Andrew Metcalfe of Warwick Medical School and UHCW NHS Trust.
Professor Edward Davis of The Royal Orthopaedic Hospital and the University of Birmingham said the findings were “by no means a condemnation of the robotic systems,” adding that more research is needed to understand the ideal positioning and personalization of knee replacements.
More Time and Higher Cost
Robotic procedures took an average of 10.5 minutes longer and cost around £950 more than conventional surgery. Based on the first-year results, the robotic approach was not considered cost-effective within current NHS cost limits.
Robotic assistance is currently used in about 6% of knee replacements in the UK, compared with 16% in the US and 42% in Australia. The technology gives surgeons greater control over cutting angles and implant positioning, allowing aspects of the procedure to be adapted to a patient’s anatomy.
Researchers will continue following participants for 10 years to determine whether the greater surgical precision leads to longer-term benefits, including fewer repeat operations.
Looking Ahead
The findings suggest that greater technological precision alone may not be enough to improve recovery. Future advances will need to show how robotic accuracy can be translated into outcomes that patients can actually experience.
In healthcare, the study highlights an important lesson: new technology must not only improve how a procedure is performed but also deliver measurable benefits for the people receiving it.