PDF Basket
Implants are widely used in orthopaedic, maxilla-facial and oral surgeries, and are typically made of metal alloys. The implantation process usually involves drilling a hole into a bone before forcing the implant inside, holding it initially through stress (pressure). For the implant to succeed, the bone must heal around the implant, securing it in place.
“If everything goes well, the implant stays in place for a very long time – possibly forever,” explains Guillaume Haiat, research director at the CNRS and BoneImplant project coordinator. “If not, then you have kind of a vicious circle, because without good healing the interface is not solid, which induces micromovements between bone and the implant,” he says. This movement prevents healing, causing the implant eventually to fail.
In the BoneImplant project, funded by the European Research Council (ERC), Haiat led a consortium of researchers which developed innovative quantification methods to monitor the success of implants. The research was designed to have practical impacts on patients, and the project results directly led to the founding of two new biomedical start-ups.
Modelling, surgery and quantification
First, using a range of computer modelling techniques, the team created intricate simulations of implants. This included analysing fluid dynamics in nanoscopic cavities, tiny holes in the bone which are instrumental to the bone healing process – known as remodelling phenomena.
“The precise mechanism of this remodelling is not well-understood, but we know that it’s related to fluid flows into these cavities, because that’s how the cell will feel and respond to the stress of the implant,” explains Haiat.
As the project was conceived to go beyond scientific advances and have a practical impact, the researchers also used experimental surgery to allow for direct monitoring of implants. These surgeries used a new type of implant designed specifically for these experiments, shaped like a coin.
“We have a standardised situation for doing the measurements in a relatively simple and reproducible way. And that’s very important, if you want to understand what’s going on,” Haiat notes.
The third part of the project focused on developing multimodality experimental measurement techniques, to quantify and extract data from the newly installed implants. This included neutron microtomography, Raman spectroscopy, and an innovation from the BoneImplant project: “We are the first ones to use ultrasound to look at the bone implant interface,” adds Haiat.
Founding new start-ups
“In this project, we go beyond the fundamental science and up to the patient bed,” says Haiat. “Meaning we create companies and medical devices to actually improve the patient’s health and provide personalised medicine.”
The results from the project led to two start-ups. WaveImplant, which has been running for a few years already, has created a medical device that uses quantitative ultrasound to measure the stability of dental implants. The system can be used by surgeons to decide how to adapt their surgeries. Human clinical trials are expected to take place next year.
A newer company, ImpacTell, was created in November 2022. This start-up uses innovative acoustic methods developed in the project to measure the stability of hip implants. When implants are hammered in by surgeons, they are guided by specific noises that suggest the implant is stable – and mostly by their own proprioception. “The device we develop helps to quantify this feeling,” adds Haiat. Clinical trials are expected in 2025.
Inspiring international collaborations
BoneImplant was an international project that involved collaborations with researchers from many countries including Korea and France. The ERC helped in hiring a South Korean postdoctoral fellow in Haiat’s lab, leading to a further project funded jointly by the French and Korean governments.
And thanks to the EU’s support and the success of the project, Haiat is now heading a French-Canadian lab, including over 50 scientists working to further the BoneImplant project. “That’s also thanks to the ERC, and to European recognition,” concludes Haiat.