Evaluation of novel implant fixation technology with a new pre-clinical testing method

Lead Research Organisation: Imperial College London
Department Name: Mechanical Engineering

Abstract

Every year in the UK, more than 300,000 hip, knee, shoulder, ankle or elbow devices are implanted into patients for the treatment of orthopaedic pain, disease and trauma. Secure fixation of these implants in bone is essential for the procedure's success, yet is challenging to achieve as bone is a living tissue that adapts and changes postoperatively.

Researchers and industry strive to develop new technologies to improve fixation, with many aiming to take advantage of bone's living response by enabling it to grow into the implant. The design intent of these new technologies is always well-meaning, but to protect patients, it is necessary to pre-clinically test them, to confirm they are both safe and achieve their aim. However, there is a lack of appropriate methods for testing this.

Traditional laboratory pre-clinical testing methods do not allow for testing with living bone samples and thus cannot measure implant bone ingrowth/adaptation. Live animal testing has ethical issues, is expensive and is complicated by anatomical differences and unknown loading. Computational models require input and validation data and so require a previous laboratory/animal/clinical study. The other alternative is clinical trial, which is effectively experimenting on patients. It also often requires years/decades of waiting to determine the outcome, and thus is only suitable as the final step of new product development.

This research project aims to overcome limitations in pre-clinical testing by using a bioreactor system to enable implant fixation technologies to be tested against 'living' bone in the laboratory. The developed methods will be validated with established clinical technologies, before being applied to pre-clinically test a novel implant fixation concept.

The long-term ambition for this research is to lower the risk for patients enrolling on clinical trials, reduce the need for ineffective live animal testing, and improve orthopaedic implants through enabling fixation technology to be optimised for in vivo performance.

Planned Impact

If the research objectives are met, we will have 1) developed and validated new pre-clinical testing methods for evaluating how implant fixation technologies interact with living bone tissue, and 2) used them to advance the technology readiness level of a new additive manufactured fixation concept.

The new pre-clinical testing methods will benefit society:

1) They will lower the risk for patients enrolling on clinical trials. Through understanding how living bone responds to a new implant, the risk of unexpected failure is reduced.

2) They will allow implant fixation technologies to be optimised for implant bony ingrowth. This will lead to stronger and more reliable implant fixation, and would benefit patients through lowering the risk that they will need a second revision procedure, and by allowing them to return to more demanding recreational/work activities sooner without risk of compromising their implant.

3) They will reduce the need for live animal testing for implant development, which is ethically questionable and is passionately opposed by members of the public.

The new pre-clinical testing method will also benefit the economy:

1) The UK has a world-leading orthopaedic industry. The new testing method will lower the cost of product development through avoiding the need for costly and ineffective animal testing, and by decreasing the risk of a failed clinical trial.

2) Through enabling implant fixation technology optimisation, the method will also help industry maintain its competitive edge by enabling companies to develop implants that outperform their competitors. This will allow UK industry to increase its share of the global orthopaedic implant market, which is estimated to be worth £35-40 billion.

3) Through developing new IP and licensing this through our project partner, we could enable industry/other centres of excellence to adopt our new methodology. It would also give our project partner a competitive edge in field of testing biomedical materials.

If the novel fixation concept passes the new pre-clinical tests, and is developed into a clinical technology, then it would also benefit patients by:

1) Lowering the risk of inadvertent intra-operative fractures during implantation. Current fixation technologies that allow bone to grow into the implant commonly need to be hammered into bone and the resulting high forces can cause fractures in extreme cases. The new fixation concept can be inserted at much lower forces, minimising this risk.

2) Enabling smaller, less invasive implants to be fixed reliably in bone thus allowing for minimally invasive procedures that avoid the need for lengthy hospital stays and rehabilitation programs.

The new fixation concept could further benefit the economy:

1) Through creating a spinout, or through a licensing agreement with an existing orthopaedic manufacturer, the technology could have impact in the orthopaedic implant market, creating jobs and leading to increased tax revenue.

2) Its adoption clinically could also benefit the UK's growing additive manufacturing industry by generating machine sales, and promoting the technology's capability.
 
Description We have developed a new way to monitor implant fixation wirelessly using a piezo transducer. In the long-term, this could enable smart implants that can detect complications such as implant loosening early. In the short-term, this could provide a way to monitor in real-time implant bony ingrowth in a bioreactor model.

We have developed new technology to optimise implant fixation in bone, designing implants could prevent long term bone loss

We have demonstrated that there is no universal limit for implant bony ingrowth, rather, implant design factors and rehabilitation (e.g. early loading) has a very important role that must be considered when developing implants.

We have developed a novel method to evaluate implant-bone fixation in the lab, using a bioreactor. This was the crux of the grant proposal and has enable new technologies to be designed for enhance bone growth onto and around implants, while also reducing live animal testing burden.
Exploitation Route The novel bioreactor method changes what can be achieved by researchers and industry in the lab when designing new implant technology. It enables cheaper, earlier stage comparison of novel technologies in a carefully controlled environment. This allows the most promising technologies to be selected for expensive preclinical/clinical trial. Importantly, the method contributes to the 3Rs (replacement, refinement, reduction of live animal testing), providing the only lab-based alternative to live animal testing for evaluating how bone adapts to novel implant technologies.

The sensor for monitoring implant fixation could be used be orthopaedic implant manufacturers to enable smart implants for routine clinical use. Academically, it could be used to provide insight to the mechanism of implant bony ingrowth, providing insight beyond end-of-test imaging, which could impact the pre-clinical testing of implants.
Sectors Healthcare

 
Description The novel method generated enabled my team to demonstrate proof-of-concept for a novel implant fixation technology. This would not have been possible without the novel bioreactor method developed in this grant as live animal trials are too costly/ethically impactful for early stage proof-of-concept research. The novel method allowed us to evaluate the technology and generate the proof-of-concept data. The proof-of-concept data has led to translation funding (e.g. UKRI Impact Acceleration Account, Imperial College London), patent application, and spinout formation (Embed Biotech). We are now pursuing commercialisation of the novel technology through the spinout. The key step that has enabled this impact was being able to test the hypothesis using the new method developed in this grant (in work package 4).
First Year Of Impact 2021
Sector Healthcare
Impact Types Societal

Economic

 
Description Bioreactors to Replace Animal Testing in Bone Research
Amount £100,000 (GBP)
Funding ID NC/Y500562/1 
Organisation National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs) 
Sector Public
Country United Kingdom
Start 09/2024 
End 09/2028
 
Description EPSRC Doctoral Prize Fellowship - Thomas Hall
Amount £68,004 (GBP)
Funding ID EP/W524323/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 09/2022 
End 10/2023
 
Description EPSRC Impact Acceleration Account - Closed-Loop Control of Bone Growth Around Implants
Amount £4,864,429 (GBP)
Funding ID EP/X52556X/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 08/2022 
End 09/2023
 
Title Bioreactor analyses of tissue ingrowth, ongrowth and remodelling around implants: An alternative to live animal testing 
Description We have developed a novel lab-based approach to evaluate how bone adapts to implants. Tissue is bought to the lab within 1-2 hours of animal tissue, and carefully prepared in a sterile environment, then house in a bioreactor that keeps the bone viable for up to 28 days. Bony adaptation around implants can then be evaluated. The approach contributes to the 3Rs by eliminating the need to test on living animals for early stage research. Some consider working with ex vivo tissue replacement, others a refinement. Also contributes to reduction as increase the amount of samples that can be tested per animal sacrificed. 
Type Of Material Model of mechanisms or symptoms - in vitro 
Year Produced 2023 
Provided To Others? Yes  
Impact This has led to a new collaboration with SINTEF (materials industry, Norway). It has led to two further research grants. It has led to an invited talk at the European Orthopaedic Research Society conference in Rome (2021), in a special symposium dedicated to the 3Rs. It also enable my team to preclinically test a novel implant technology, for which we are now pursuing intellectual property and commercialisation with our spinout Embed Biotech. Finally, the research led to an award from the NC3Rs to increase uptake of the method and reduce reliance on live animal testing in bone research. 
URL https://doi.org/10.3389/fbioe.2023.1054391
 
Title Device to functionalise an implant 
Description We invented a technology to stimulate bone growth onto and adjacent to an orthopaedic implant with an implantable electronic system. The UKRI New Investigator Award enabled us to test this new implant fixation technology in the laboratory (work package 4), generating the pilot data that underpinned the patent application. The patent will be commercialised via our spinout company Embed Biotech. 
IP Reference 2309926.0/GB/PRV 
Protection Patent / Patent application
Year Protection Granted
Licensed Commercial In Confidence
Impact The patent will be commercialised via our recently formed spinout company Embed Biotech.
 
Company Name Embed Biotech Limited 
Description  
Year Established 2024 
Impact Company formed in Q1 2024 - currently fund raising.
 
Description Patient and Public Involvement Group 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Patients, carers and/or patient groups
Results and Impact Two meetings:
4th March 2020: Research Associate Nupur Kohli presented focusing on this research.
9th December 2020: Dr Richard van Arkel (PI) provided a short update on the research (virtual meeting).

A short presentation, followed by extensive discussion with patients regarding our research objectives. We use this as a forum to ask patients questions such as: "Would you rather research effort prioritises short-term objectives like return to work, medium-term objectives such as function/recreational activity, or longer-term (>10 years) priorities such as reducing risk of revision?". The patient responses is one of the factors we consider when prioritising what we focus on in our laboratory based model of implant fixation.
Year(s) Of Engagement Activity 2020
 
Description School Talk (Brampton Manor, East London) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Brampton Manor is a very large school in East Ham, Newham with nearly 600 in the Sixth Form. Newham is a borough in the Inner East of London, which experiences significant problems with poverty and inequality. The poverty rate in Newham is 37% - ten percentage points higher than the London average and, among London boroughs, lower only than the poverty rate in Tower Hamlets. At Brampton Manor Academy, 76% of our pupils speak English as an Additional Language (national average = 17%), 58% receive Free School Meals (national average = 29%), 97% of the Year 12 cohort are from BAME backgrounds and the vast majority are the first in their family to enter higher education.

I visit Brampton Manor annual to discuss careers in engineering and my research. In my 2020 (virtual) visit I demonstrated some of our latest research to highlight how engineering is advancing the life sciences and medical research through this collaborative project investigating the link between mechanical engineering, implant design and bone biology.
Year(s) Of Engagement Activity 2020