Serving implant patients by detecting corrosion on a nanoscale
According to the Canadian Institute for Health Information, more than 137,000 joint replacement surgeries took place in Canada in 2020, costing the healthcare system north of $1.4 billion. And each year, 8,000 to 10,000 of these replacements are unsuccessful and require risky revision surgery that are nearly twice the price of the original surgery not to mention huge indirect cost to the patients.
Understanding why these implants fail is at the core of Yolanda Hedberg’s work as a professor in the Faculty of Science. A corrosion science expert, Hedberg has dedicated her research to analyzing and predicting material deterioration that could result in health hazards or environmental pollution. Joint implants are of special interest to her as a BJI Scientist. For patients in need of joint replacements, receiving a durable implant means avoiding painful bone and tissue damage, infection, and multiple surgeries along with drastically improving their quality of life. Creating implants that can withstand the daily stress of joint movement, however, is a big challenge.
“When you think about it, joints are in motion, and this means there is a lot of wear,” says Hedberg. “From an engineering perspective, it is really hard to make joint implants as good as natural joints. You have to connect different materials and that increases the risk of incompatibility, which can lead to corrosion.”
Failed implants retrieved from patients can provide important clues in understanding what went wrong. Hedberg is planning on taking implant analysis to the next level with a new optical coordinate measuring machine. The machine can detect and map how much material has been lost due to wear and corrosion, which will provide researchers with invaluable insights into why implants fail.
“We currently use electron microscopy and optical microscopy to score corrosion severity and material deposition. An optical microscope needs to be electrically conductive, and you can only put it at a certain angle because the detector is fixed. The new instrument has many different axes. It rotates around the implant and measures the surface really fast without making contact,” says Hedberg. “We can exactly measure how much volume of mass has been lost in that implant. That is a game changer for Western and for implant retrieval-related research.”
To support her work, Hedberg was awarded a 2022 Catalyst Grant by the Bone & Joint Institute. The grant will provide $30,000 to help Hedberg and her team conduct research on retrieved hip implants. The team will measure and analyze material loss due to corrosion on 129 implants of a certain design.
Hedberg hopes this interdisciplinary research project will better position the team to secure major funding to develop higher quality implants, detect faulty designs early on, and identify high risk patients.
“You already need to have funding in place to be successful in applications for other grants, and that’s where the Bone and Joint Institute and their seed grants can really help. You can show in your CV that you and your co-applicants already work together and already got grants, and it increases your chances by a lot.”
In the meantime, she has joined the effort of another interdisciplinary team at BJI that leverages many experts and methodological strengths to tackle orthopaedic infections. When implants get infected, it is difficult to assess if the implant needs to be taken out or if infection around the implant might heal itself. That often means additional surgeries, long recovery times, or even amputation in some cases.
Team members like Chief of Surgery at the London Health Sciences Centre and St. Joseph's Health Care Emil Schemitsch) have had their eyes on equipment that could improve patient outcomes: a mass spectrometry knife, or iKnife. This would be the first at Western University. An iKnife would provide a minimally invasive way to make an informed decision and potentially spare patients the ordeal of surgical revisions and recovery.
To secure funding for the iKnife and other equipment that would advance Hedberg and many other researcher’s work, BJI leaders prioritized think tanks to identify synergies and build cohesive large-scale programs of research in which all team members and equipment requested complemented each other towards a common goal.
The large interdisciplinary team applied for a $7.2 million Canada Foundation for Innovation (CFI) grant this year. BJI’s think tanks played a pivotal role in preparing the grant applications by bringing researchers with a wide range of expertise together, including surgery, microbiology, medical imaging, genomics, drug delivery, materials chemistry, and biomedical engineering. Convening expert from such different fields is not easy and that is why the CFI proposal would have never seen the light of day without the institute, Hedberg says.
“The CFI proposal requirements are very complex. You need ten core applicants and a large number of collaborators, and they have to meet very specific diversity and interdisciplinary criteria. There’s a 30% success rate, so you really need to check those marks,” Hedberg says. “The BJI was instrumental in getting a collaborative team together. They set up think tanks to bring everyone together and work on the proposal. The proposal has huge potential for finding solutions that will improve patient outcomes and reduce burden on health and social systems.
