Is robotic surgery achieving better results for knee replacement patients?

What results are achieved in knee replacement today?

Whilst the majority of knee replacement patients claim to have ‘excellent’ or ‘very good’ results from their surgery, nearly 20% of patients are not entirely satisfied.

This has encouraged both technology manufacturers and surgeons to search for ways of improving outcomes - as is most often the case in medicine.

Whilst it’s clear that high volumes of knee replacement surgeries performed by a surgeon correlates with better results, the key question we now ask is: ‘could robotics lead to even better results across the board?’

The differences between robotic and conventional knee replacement surgery

The primary difference between robotic-assisted knee replacement surgery and conventional replacement surgery is the way surgeons achieve precision and accuracy.

Conventional knee surgery relies on the surgeon's skill and experience to make accurate cuts and place the implant correctly, whilst balancing soft tissues i.e. ligaments.

By contrast, robotic-assisted knee replacement surgery uses advanced technology to create a computerised 3D model of the patient's knee joint, which can allow for more precise surgical planning and execution - and less variability. A robotic-arm is then programmed to guide the surgeon’s cuts, based on the CT scans.

Robotic knee replacement, recent clinical research

This is a summary of recent clinical research into robotic assisted knee replacement surgery, its outcomes for patients, and the differences in results when compared with the manual, conventional approach to knee arthroplasty.

2020 systematic review & meta-analysis*

* Meta-analysis: examination of data from a number of independent studies of the same subject, in order to determine overall trends.

Several studies have been conducted in recent years to evaluate the effectiveness of robotic knee replacement surgery. A 2020 systematic review and meta-analysis of 18 studies found that robotic-assisted knee replacement surgery resulted in better alignment and fewer complications than conventional knee surgery.

The study concluded that robotic-assisted knee replacement surgery was a safe and effective alternative to conventional knee replacement surgery with accuracy leading to marginally better clinical outcomes.

A 2021 EFORT Open Review

A 2021 EFORT Open Review of ‘The current state of robotics in total knee arthroplasty’ found that patients who underwent robotic-assisted knee replacement surgery had better postoperative range of motion, fewer complications, and shorter hospital stays than those who underwent traditional knee surgery.

However, overall the review concluded: “While early robotic systems have failed to confer any meaningful clinical benefit and justify the excess costs, newer robotic systems have demonstrated promise by minimising soft tissue damage, reducing hospital stay and improving short-term functional outcomes.”

Finally, other more recent studies have confirmed the robotic knee delivers precision in mechanical alignment with improvement in early functional outcomes. However, long term functional outcomes and implant survivorship are as yet to be verified.

Longer term and multiple site studies are underway

Several large-scale clinical trials are currently underway to evaluate the long-term outcomes of robotic-arm assisted knee replacement surgery, including the potential benefits for patients with severe knee deformities.

One such trial, the Mako Total Knee Replacement Study, is a multi-centre (hospitals) study involving over 1,000 patients undergoing robotic-arm assisted knee replacement surgery. The study aims to evaluate the long-term outcomes of robotic knee replacement surgery, including patient-reported outcomes, functional outcomes, and implant survivorship.

Robotics is such a promising new era in knee replacement

Robotic-assisted knee replacement surgery represents a promising technology for a procedure which whilst very successful, can be unsatisfactory for some patients.

Overall, both manual and robotic-assisted approaches have shown to have similar outcomes for knee function and survival, and are equally safe. More studies are now needed to fully evaluate the long-term benefits of robotic-arm assisted knee replacement surgery, and the variability between surgeons and sites where knee arthroplasty, using this technology, takes place.

A final word from Compare my Care about choosing a surgeon

Since both manual and robotic-assisted approaches are dependent on the skill and experience of the surgeon, it remains crucial to be in the hands of an experienced knee replacement surgeon, with an established high volume robotic and/or manual knee replacement practice. Patients should not be afraid to ask their surgeon for their volumes and outcome data but Compare my Care can provide this insight.

With thanks to Mr Jonathan Miles, Consultant Knee Surgeon at the Royal National Orthopaedic Hospital and privately at The Wellington Hospital (part of HCA Healthcare UK) in London. Mr Miles uses the MAKO Robot almost exclusively to perform (total and partial) knee replacements. He is also one of the country’s leading revision surgeons, for patients’ who are referred to him after primary knee or hip replacement has failed.