Robot Assisted Knee Surgery

We’ve changed our position on the use of robots in knee replacement surgery. Nick London explains what’s changed and why.

A year or so ago, you could have summarised our position on the use of robots in knee surgery as this: with some reservations, the evidence suggested we were moving to a point where the long-term advantages of robot-assisted knee replacement surgery for total knee replacements were possibly going to outweigh the increased risk or complications involved in using the new technology.

We trained to use a robotic system suitable for our preferred implant. We offered robot-assisted surgery on this very site.

You may notice that we have removed that offer.


Robot assisted knee surgery: unconvinced by the evidence

This summer we reviewed our position on robots and the evidence was clear: we have not seen any increase in the volume of strong data to support the short or long-term benefits of robot-assisted surgery in total knee replacement when compared with conventional alignment surgery.

We have, however, seen a recent review of literature which reached the conclusion that “robotic-assisted mechanically aligned total knee arthroplasty [TKA – that is, total knee replacement] does not lead to better clinical and radiological outcomes when compared to conventional TKA.”

Our view was confirmed via discussion at the European Knee Society earlier in the year.

Compounding that view are the continuing reports of complications, as explored in this paper: Complications and downsides of the robotic total knee arthroplasty: a systematic review.

Finally, our own experience of robot-assisted surgery (and our broader experience of thousands of successful knee replacements over the last 25 years) left us unconvinced that it offered any real benefits over conventional knee replacement with conventional instruments.

To be clear, we’re not suggesting we have had any great swing against the use of robots. Our cautious acceptance of them in total knee replacements 12 months ago was based on an expectation that the direction of travel in terms of supporting evidence would continue on an upward trajectory. We simply haven’t seen that.


Robots in partial knee replacement

If our position regarding robots in total knee replacement has shifted, that’s not the case for partial knee replacement. We have never believed robot assistance is the optimal choice for partial replacement. We still don’t.

That’s a view based on our experience with the Persona Partial Knee (PPK) from Zimmer Biomet (the implant we use for medial partial knee replacements, that is, replacements of the inner compartment of the knee), and the Physica ZUK from LIMA Corporate (the implant we use for replacements on the outer — lateral — side of the knee).

The PPK, launched more than 5 years ago, has the lowest reported revision rates (that is, requiring correction) of any partial knee implant, with exceptional outcome scores in its first performance review and our own 5-year review imminent. The Physica ZUK has the best 10–15-year survival data of any partial knee implant. You’ll find the data in the latest report from the National Joint Registry (on page 184).

The results achieved using implants designed for robot assisted surgery don’t compete with results achieved using the best conventional implants and techniques. In fact, we continue to have grave concerns that the increased risks of robotic surgery are not compensated by any short or long-term benefits to patients. Data from the Australian Joint Registry latest report suggests that the chances of requiring revision surgery after a robot-assisted partial knee are almost three times higher than National Joint Registry data from of the partial knee implants we use with conventional surgery.

> Read our article on which knee implant is the best


“Every day is your best day in surgery”?

There’s a lot of marketing behind the use of robots in knee surgery, much of it extraordinary and, in our opinion, highly misleading. You’ll often find certain hospitals, companies, surgeon groups and individuals making statements along the lines of ‘with a robot, every day is your best day in surgery’.

You might have seen it suggested that, even if robot assistance can’t yet compete with an experienced surgeon working with proven implants and instruments, it may be able to elevate the outcomes achieved by junior surgeons.

This is not true.

A robot only ever assists. It doesn’t carry out the surgery. The surgeon leads, the robot helps, but the surgeon has the expertise to know if the robot is attempting to take things down an incorrect path. If the robot fails, the surgeon can simply carry on without it. An inexperienced surgeon is unlikely to be ‘improved’ by a robot, especially if they don’t have the experience to challenge or take over from it when required.

Yet whilst a robot may not make a less experienced surgeon better, it does increase the level of risk.

It is entirely possible to achieve excellent results using robot-assisted surgery, but that’s not the same as saying excellent results were achieved because a robot played a part.

> Discover more about partial or total knee replacements


What to do if you are considering robot-assisted knee surgery

If you are convinced that robot-supported surgery is right for you, it’s important you understand the following:

  • The data clearly show that surgical risk will increase
  • You may pay more than you would for conventional knee replacement, and there’s little evidence supporting any cost-benefit
  • Your outcomes may be excellent, but that may have little (or nothing) to do with the robot. Because of this, you may wish to see the surgeon’s outcome data with and without the robot and compare this with other surgeons. You can do this via the National Joint Registry.


Robots and your knee — what happens next?

Despite our shift in respect of robots, we certainly don’t expect the clamour and noise to subside. We will keep the situation under review. We may reach a point where there is clear evidence of clinical benefit over risk for low volume and perhaps even high-volume surgeons, although the latter feels rather less likely at present. We may reach a point where there’s a cost benefit too.

What’s clear is that we are not there yet, and the surgeons of Yorkshire Knee Clinic suspect that position is unlikely to change in the near future.

That’s why we have taken the decision to withdraw robotic-assisted total knee replacement from the services we offer. It’s also why we continue not to offer it for partial knee replacement.

If you would like to explore your (non-robot-assisted) options for knee surgery or simply discuss the position outlined above, contact us or phone us on 03453 052 579.

> Discover more about Nick London
> Discover more about partial or total knee replacements
> Discover more about osteoarthritis, symptoms & treatments

Prof. Nick London

Prof. Nick London

Private appointments weekly at The Duchy Hospital Harrogate & Nuffield Hospital Leeds

Private Secretary

Lou Nellies
01423 369 119

Email Nick


Knee replacement x-ray

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