A range of ground-breaking genetic tests could help predict whether joint replacements succeed or fail. These new genetic tests are poised to help the UK meet its goal of becoming a world-leading ‘science superpower’ by 2030, UKRI notes.
The Medicines and Healthcare products Regulatory Agency-registered Orthotype tests from ExplantLab were launched this week at the Artificial Intelligence in Orthopaedics conference at the Royal College of Surgeons.
The tests have been developed with the backing of Innovate UK and the Academic Health Science Networks for the North East and North Cumbria, in collaboration with:
Newcastle University
University Hospital of North Tees
Nuffield Health Tees Hospital
Hospital for Special Surgery, New York
Royal Perth Hospital, Australia
Testing for allergic reactions
Orthotype tests identify genetic markers in saliva or blood samples for specific variations of human leukocyte antigen (HLA) genes, which regulate immune responses.
These genes indicate whether patients will develop an allergic reaction to cobalt chrome, a type of metal found in many joint replacement implants.
Predicting risk
David Langton from ExplantLab explains:
By sequencing DNA in saliva swabs and blood tests from over 600 joint-replacement patients around the world, we established that those who suffered complications carried specific variations of the HLA gene family.
We then used our findings to develop a machine-learning algorithm called Orthotype that uses genetics to accurately predict whether a patient is at risk of reacting to a joint replacement made of a cobalt chrome (CoCr) component, often referred to as an allergic reaction to the joint implant.
Innovation driven by necessity
The pandemic saw the number of hip and knee replacements fall, due to the pressures on the NHS. There remains a significant backlog of cases which has led to increased waiting times.
The problem is worsened by the fact that not all joint replacements are successful. Worldwide, it is estimated that 10% to 20% of the procedures being carried out are revision surgeries, where original implants have failed. Up to 44% of failed knee joint replacements show evidence of an adverse CoCr reaction.
In addition, around 20% of patients return post-surgery with joint pain. A genetic test that can help reduce the adverse effects of implants may reduce the need for post-operative chronic pain management and repeat surgery.
This will help to deliver better orthopaedic care and health outcomes for patients as well as potentially reducing NHS waiting lists.
Innovation in othopaedics
Mr Jeremy Latham, Consultant Orthopaedic Hip Surgeon in Southampton, said: We know that the majority of patients have an excellent outcome following joint replacement surgery. However, some people do experience an adverse reaction to implants that are made from cobalt chrome alloy.
The use of Orthotype will help us identify these patients so that we can make better decisions about the best implant for them. In the age of personalised medicine and shared decision making, this is the type of innovation that we should be adopting in orthopaedics.
Why artificial joints fail
While joint replacement operations tend to be successful, a significant number of patients return post surgery with unexplained pain and inflammation which can result in implant failure.
Sometimes this is because the joints have become unstable or infected but over the past 2 decades an allergic reaction to the ‘debris’, or metal particles, shed by a joint implant has been increasingly recognised as a contributing factor.
As well as chronic pain and inflammation, this can cause irreparable tissue damage. In the most severe cases, people can develop an autoimmune-like response to their implant, leading to a more serious disorder known as ‘metal hypersensitivity’. It is in these cases that joint revision surgery may be recommended.
Information is empowering
Sally, aged 66 from Leeds has had knee pain for over 40 years. She said:
When the pain began stopping me doing the things I wanted to, like going for long walks, I knew I needed some help. My doctor started discussing knee replacement surgery. I heard about the Orthotype research in the news and thought having the test before I had surgery would be a good idea.
Sally accessed the test on compassionate grounds from ExplantLab prior to launch.
She said:The test was easy to do at home, and I sent it back in the post. A couple of weeks later I learned that I have the genes that might make me more likely to react badly to the most commonly used knee replacement implants.
Having this information is empowering because my doctor can use it to choose the best kind of implant for me, which makes me feel a lot more confident about having the surgery UKRI notes.
Personalised orthopedic medicine
It is hoped that the launch of Orthotype could herald a new surgical era of personalised medicine in orthopaedics in which individuals undergo genetic testing prior to receiving implants.
Innovate UK, which part-funded the research into Orthotype, believe that it will relieve the burden faced by patients and the already buckling health service. Orthotype’s use in standard clinical practice is also an additional demonstration of Britain’s thriving innovation in science and technology.
Richard Hebdon, Director of Health and Life Sciences at Innovate UK said: As health systems come under increasing pressure to serve a growing, ageing population, it is inevitable we’ll see more of a move towards personalised medicine.
The traditional one-size-fits-all approach simply will not meet the increasing complexity of society’s needs. Therefore, innovations such as Orthotype, that inform and enhance clinical decision-making on a personal, practical level, will be vital in enabling a fit-for-purpose transformation.
A transformation that could help cement Britain’s position as a leader in scientific innovation on the international stage.
First-in-class genetic tests
The MyOrthotype saliva-based home test kit is available for pre-operative joint replacement patients to order online via the ExplantLab website.
Surgeons and clinicians can order more detailed blood-based versions of the Orthotype tests via the pathology laboratory services in their hospitals. This includes a post-operative combined test that can be used to diagnose metal sensitivity in people who have already undergone surgery.
