Development of an instrumented hammer to assess the stability of hip implant during surgery: assessment of the commercial feasibility

Project Information

Impactor

Grant agreement ID: 101062467

DOI

10.3030/101062467

Project closed

EC signature date 18 October 2022

Start date 1 November 2022

End date 30 April 2024

Funded under

• European Research Council (ERC)

Total cost

No data

EU contribution

€ 150 000,00

Coordinated by

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE CNRS
France

Periodic Reporting for period 1 - Impactor (Development of an instrumented hammer to assess the stability of hip implant during surgery: assessment of the commercial feasibility)

Reporting period: 2022-11-01 to 2024-04-30

Summary of the context and overall objectives of the project

Impactor has allowed the creation of the start-up company ImpacTell, who is developing an innovative and patented medical device with a proof of concept established in preclinical studies. The objective of this surgical hammer, a class Im medical device named Smart-Hammer, is to provide orthopedic surgeons with a decision support tool to ensure an objective and optimal conduct of surgical protocols during total hip replacement (THR). This new tool responds to an unmet clinical need to obtain a reliable estimate of primary stability, which is the main determinant of surgical success. Starting in 2026, ImpacTell will help surgeons achieve optimal primary stability of implants while reducing the risk of intraoperative fracture or necrosis due to excessive mechanical stress on the bone.
ImpacTell was created in November 2022 by Stéphane Perche (President), Félix Berriat (General Manager) and Guillaume Haïat (Scientific Director). Guillaume Haïat is a graduate of the Ecole Polytechnique and Director of Research at the CNRS (French National Center for Scientific Research). He is the inventor of the technology. He has 15 years of experience in academic and industrial research in implantology. Stéphane Perche is an entrepreneur with a degree from the École Polytechnique and extensive experience in management, finance and strategy. He was a director of Deutsche Bank in London. Félix Berriat is a graduate engineer from the École Polytechnique. After a master's degree in biotechnology at the Technical University of Denmark, he completed a PhD at the Paris Brain Institute.

The implants used in THR are impacted with a hammer to ensure their stability. The technology used is based on an instrumented hammer that allows analysis of the temporal variation of the force exerted by the hammer on the implant during an impact. The insertion of the implant into the bone leads to a stiffening of the bone-implant system which is measured at each impact by our hammer equipped with a piezoelectric force sensor. Quantitative and objective data reflecting the primary stability of the implant (which is the main criterion for surgical success) is provided to the surgeon in real time. This information allows the surgeon to adapt the number and energy of impacts to reduce the risk of i) aseptic loosening and ii) intraoperative fracture, which leads to a reduction in re-do's and complications as well as a safer surgical procedure. This technology does not require any additional action on the part of the surgeon and does not modify the surgical protocol. The proof of concept has been validated in studies on anatomical subjects very close to the clinical situation.

By optimizing primary stability during surgery, Smart-Hammer will reduce the rate of revision prostheses due to aseptic loosening and periprosthetic fractures. The cost of a first-line THR is estimated at approximately €10,000 in France and $40,000 in the United States. For the patient, a failure implies the need for a revision surgery, the cost of which is approximately 30% higher than the initial intervention. For the practitioner, a failure has important consequences on his or her reputation and the trust granted by the patient. As our market study in France shows, orthopedic surgeons are interested in the Smart-Hammer, which does not modify the operating protocol and provides additional assurance of good fixation of the THR, including for the training of young surgeons.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

The work performed during Impactor was divided into 5 activities that are summarized below.
Activity 1. Conceiving and creating the minimum viable product.
Four different activities have been carried out.
First, we have worked on the integration of the force sensor within the head of the hammer. We were successful in conceiving this device using quartz materials and a dedicated electric circuit. This breakthrough allows to manufacture our sensor directly. The sensor is resistant to the autoclave.
Second, we have carried out a pre-study on the integration of the electronic and on the human-machine interface. We focused on the design of the handle and on the definition of the screen and of the electronic component that can resist to the autoclave. We have also defined a robust user-case scenario.
Third, we have optimized the signal processing by defining optimal filtering and averaging of the signal.
Eventually, we have worked on the modeling of the insertion of the femoral stem, which was useful to define the aforementioned signal processing technique.
Activity 2 (M6-M18). Validation of the minimum viable product
The MVP consisting of the home-made sensor was first validated in silico by performing many numerical simulations in order to determine how to position and size the components.
Then, we used a bone-mimicking phantom in which we inserted the implant in order to validate the MVP in a more realistic manner.
Eventually, we worked with animal bone (instead of cadavers) because anatomical subjects were not necessary to obtain the final validation.

Activity 3 (M1-M18). Regulatory issues.
We have validated the class of the set-up, which is Im as well as the regulatory pathway, which implies setting up a Quality Management system and obtaining pre-series on which various tests will need to be carried out including biocompatibility, validation of the measurement function, electromagnetic compatibility, electric safety and usability.

Activity 4 (M9-M16). Market analysis and determination of how the market will be engaged.
We have performed an additional market study to validate our choices. Moreover, we have established a clear marketing plan, which is confidential.

Activity 5 (M1-M18). Business strategy.
Following the creation of Impactell, the cofounders have invested 40k€. A sloid business plan was devised. We have then obtained the Deeptech label from the BPIFrance and then a subvention of 90k€. We then managed to carry out a first seed founding, which is followed by another round of Convertible bounds.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Smart-Hammer is intended for orthopedic surgeons who perform hip replacements. Our market is therefore targeted at purchasers of surgical tools, mostly healthcare institutions (pharmacies) that will act on the prescription of surgeons using the technology. Worldwide, approximately 150,000 orthopedic surgeons perform ~3 million THRs each year, with a growth rate of approximately 5% per year. We estimate the total addressable market for this application to be €160M per year. Our approach could also be useful for other implants (shoulder, knee, spine...) as well as for other surgical applications such as osteotomies (rhinoplasty) and soft tissue properties analysis for which preclinical validations have already been obtained. We plan to estimate market sizes and opportunities in additional market studies for each of these applications.

Various academic teams around the world are developing methods to assess the primary stability of orthopedic implants. To our knowledge, we are the first to develop a medical device based on a validated method on an anatomical subject. Currently, the surgeon relies on proprioception (touch, impact noise) to adapt the impacts. The alternatives are the use of cemented prostheses for which the stability problems are not important but which have many disadvantages and which are therefore less and less used.

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