- Design
- Target trial emulation using national registry data
- Population
- 697,145 knee replacements (22,111 robotic) in the UK, 2018–2024
- Primary outcome
- Five-year implant survival (all-cause revision)
- Effect
- TKR: 98.6% robotic vs 98.5% conventional; HR 1.03 (95% CI 0.86–1.26)
Using the National Joint Registry for the UK and Crown dependencies, researchers emulated a target trial across 697,145 knee replacements from 2018 to 2024, of which 22,111 were robotic. Propensity matching compared like with like.
Five-year implant survival was 98.6% for robotic and 98.5% for conventional total knee replacement (HR for revision 1.03, 95% CI 0.86–1.26). Partial knee replacement showed the same pattern. Intraoperative complications and causes of revision did not differ.
Robotic systems cost substantially more to buy and use. For a referring clinician, this means a patient asking whether to seek a robotic operation can be told that early outcomes look similar, while longer follow-up is still needed.
- Tell patients that early revision rates were similar for robotic and conventional knee replacement.
- Do not delay referral to wait for a robotic option.
- Mean follow-up was 2.5 years; longer-term differences remain possible.
- Surgeon experience and implant choice matter more than the tool for most patients.
Why it matters
Costlier technology has not yet shown it buys better early outcomes.
Don't overread it
This is observational and early; it cannot rule out a long-term advantage for either approach.
The statistics, in plain English
A hazard ratio of 1.03 with an interval from 0.86 to 1.26 means no difference was detected. Target trial emulation mimics a randomised trial using registry data, but unmeasured differences between patients can still bias the result.
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