A major £1.6 million study is underway that will pitch human skill against machine precision, as it compares the benefits of knee replacement surgery performed using a robot to a surgeon using traditional methods.
Knee replacements are very common operations; over 100,000 procedures are performed each year in the UK. But the procedure is not perfect. Although it can significantly improve patients’ conditions, some are still left with persisting pain and limitations after the operation.
Robotic surgical equipment has been growing in popularity in recent years as surgeons look for ways to improve patient outcomes. There are between 600 and 700 robots in use across the world, with 30 of those found in UK hospitals which are mostly private.
With robot-assisted knee surgery, patients receive a CT scan to produce a 3D plan of the knee. The operation is then pre-planned before the robot carries out the surgery, making small adjustments during the operation to improve the procedure. The ultimate aim of using robots is to make surgery more precise and thus damage less soft tissue, leading to reduced pain for the patient.
But although robotic surgery shows a lot of promise, it is still unknown whether it is actually better than traditional methods. Surgical robots are favoured by some for their precision and guidance, while standard instruments are preferred by others for their simplicity and ability to make greater use of surgeons’ skills and experience, without the added expense.
According to Andrew Metcalfe, who will be co-leading the study, it would cost tens, if not hundreds of millions of pounds to roll out the technology across the NHS. With the UK currently spending around £550 million every year on knee replacements, it may be worthwhile to invest in surgical robots. However, this would only be the case if the technology available makes a significant improvement to the cost and effectiveness of knee surgery.
“Are traditional instruments better or are robots better? We genuinely don’t know,” Metcalfe said. “And if one is better than the other, is that step big enough to be worth investing in? Those are two separate but related questions; what is the value of that additional technology?
“The challenge with these things is you’re using something that seems really slick, but you don’t know if it has benefit. There’s lots of examples in surgery where technology has been used and they seem like a good idea, but didn’t turn out to be any better.
“We do know that the robot makes things more precise, so. The question is, we might already be precise enough and it might be that surgeons using their own instruments are actually capable [enough] already.”
The RACER (Robotic Arthroplasty: a Clinical and cost Effectiveness Randomised controlled trial) study aims to answer the question by comparing the use of surgical robots to standard instruments, determining which of the two techniques is best at improving patient outcomes and reducing pain following surgery.
The £1.6 million randomised controlled trial is funded by the National Institute for Health Research (NIHR) and will be jointly run between University Hospitals Coventry and Warwickshire (UHCW) NHS Trust, Warwick Medical School at the University of Warwick, and the Royal Orthopaedic Hospital (ROH) in Birmingham. The research team will be led by Mr Metcalfe, from UHCW and Warwick Clinical Trials Unit at the University of Warwick, and Professor Ed Davis from ROH.
Smaller versions of this type of study have been carried out before in a few centres dotted around the world, however RACER is breaking new ground with the sheer scale of the study.
“This is probably one of the biggest questions in orthopaedics right now and we’re probably the only country that can deliver it, because we’ve got [the] level of organisation and the size to do it. The actual ability to do this sort of work is really new and exciting.”
RACER is analysing an equal number of participants in each treatment group, which means a balanced and fair comparison can be made to find out which surgical technique results in better outcomes. This will include asking questions about people’s ability to do activities and their quality of life in the long term and will also find out which method provides the best value for the NHS.
The outcome of the trial could go one way or the other. The NIHR would not have invested a large sum unless it was fully convinced that the answer was unknown, Metcalfe said.
So, if the trial finds that traditional methods are better than robots, what would this mean for robotic surgery moving forward?
“It would mean going back to the drawing board,” Metcalfe said. “The questions for the robotics community if we found no benefit would be, is there a different version of the technology or is there something they can do differently? Is it that robotics do not work or is it that we need to find a different way of using this technology to make things better?
There will be lots of data from the study to help inform that, so it may well help guide us to make our conventional instruments better or, if robotics aren’t as good as we thought, make those better.
“Hopefully, we’ll get a load of information that’s going to help us improve the care we give, whichever[ technique] is found to be better.”
Although the trial opened at the end of December 2020, activity was delayed by the Covid-19 response, when most orthopaedic services were paused. Some hospitals are now seeing patients again and the study is now accepting patients into its first sites.
The study needs 322 patients to take part, with the recruitment phase due to finish in July 2022. Patients’ recovery will then be monitored for the next 12 months and analysed before being published in April 2024. Questionnaires will then be collected two years, five years and ten years after the surgery to assess the potential long-term benefits of robotic surgery.
The Royal Orthopaedic Hospital in Birmingham and the Royal National Orthopaedic Hospital in Stanmore, London, are already open for recruitment, with a number of other hospitals across the UK (including the Glasgow Royal Infirmary, the Royal Infirmary of Edinburgh, the Freeman Hospital in Newcastle, the Royal Devon and Exeter NHS Trust, and Portsmouth NHS Hospitals) expected to open soon.