Periodic Reporting for period 3 - APRICOT (Anatomically Precise Revolutionary Implant for bone Conserving Osteoarthritis Treatment)
Reporting period: 2022-04-01 to 2023-09-30
Prevalence and incidences of osteoarthritis (OA) vary depending on age, sex and study type, but an overall prevalence of 43.3% is estimated for OA in the hand. This prevalence is higher than that seen for the hip and knee, which are far more studied. There are currently no effective interventions known to restore natural joint kinematics while alleviating pain associated with the progression of degenerative bone disease of small joints. Current treatment programmes of pharmacological and non-pharmacological modalities can present complications with long-term use, such as liver and renal failure. Surgical (arthroplasty) intervention traditionally involves a metal or pyrocarbon component articulating against a polymer component to impart flexion and extension. However, complications, such as implant loosening or fracture occur, necessitating revision surgery. Silicone based implants are to date the gold standard in finger arthroplasty and offer much reduced reoperation rates. However, they suffer from dislocation and in the long term, implant fracture rates of up to 30%. Crucially, they cannot provide a natural range of motion, and are highly invasive. Fusion of the joint is considered as a viable alternative to arthroplasty, but severely limits function for most day-to-day activities. Without treatment, the patient with joint pain, and a severely impaired quality of life.
The vision of the APRICOT project is to create a radically new type of implant for the effective treatment of OA of small joints. It is an innovative patented and highly compliant thin flexible implant, which can be positioned minimally invasively within the affected joint space, restoring the joint’s natural kinematics, without the need for healthy bone removal, differentiating it from all current implant solutions.
Success for the APRICOT concept will benefit the patient by restoring full function, reducing/removing pain in the joints, in addition to restoring dignity and empowering the patient, allowing them to return to work or contribute to their community. It will also decrease post-op healthcare costs and potential mental health issues resulting from feelings of isolation and withdrawal from society. This is particularly relevant today as people are living longer and keeping active in later life.
The vision of the APRICOT project is to create a radically new type of implant for the effective treatment of OA of small joints. It is an innovative patented and highly compliant thin flexible implant, which can be positioned minimally invasively within the affected joint space, restoring the joint’s natural kinematics, without the need for healthy bone removal, differentiating it from all current implant solutions.
Success for the APRICOT concept will benefit the patient by restoring full function, reducing/removing pain in the joints, in addition to restoring dignity and empowering the patient, allowing them to return to work or contribute to their community. It will also decrease post-op healthcare costs and potential mental health issues resulting from feelings of isolation and withdrawal from society. This is particularly relevant today as people are living longer and keeping active in later life.
In the first reporting period, the team consulted with the clinician panel to determine a suitable joint to demonstrate the concept. initially, the digital hinge joints of the hand were selected, and the thumb metacarpophalangeal (MCP) joint was identified as an appropriate candidate based on its geometry, size, and the lack of an existing dedicated solution for thumb MCP arthritis. Patient public involvement strategies were undertaken to gain an understanding of the problems faced by patients, and get an idea of which potential benefits were most important to them. Computational modelling of the thumb joint led to the development of a statistical shape model that helped the team understand how the shape of the joint varies between individuals. Design and manufacturing strategies were assessed and generated new IP for Aurora Medical. Bespoke test rigs were designed so the device could assessed under typical loading and kinematic conditions. Concepts for external fixation and internal lubricious coatings were proposed and optimised over the course of the project.
A project website was created and regularly populated with new information. The communication, dissemination, and exploitation strategy was refined, and Key Exploitable Results established. A Project Management Platform was constructed to assist with the management of the project.
Over the two remaining reporting periods, surface treatments and fixation techniques were developed that enabled the implant to function as intended, that is, with very low friction while retaining its position in the joint. Biocompatibility testing of the surface treated and untreated implant materials showed that the materials were tolerated in vivo. Mechanical testing on artificial bones showed that the implant was able to function efficiently for over one million loading cycles. Once the concept was proven in the laboratory, cadaver trials were undertaken at two centres. These trials demonstrated the effectiveness of the APRICOT implant, highlighting its ultra-low invasiveness, its ability to remain in place and supported by the surrounding soft tissue, and its ability to restore the full kinematic function of the joint over a wide range of flexion/extension angles and with smooth, almost frictionless movement. An unexpected benefit of the device was the very short surgery time.
At project conclusion, the consortium achieved the objective of proving the APRICOT concept in two ways: (i) via testing in the lab under long term repeated loading in artificial bone joints, and (ii) via testing in cadaver joints to demonstrate the restoration of full joint function. The cadaver tests illustrated that the implantation was simple, rapid (< 10 minutes), and involved little to no trauma. These very encouraging results place the project in a suitable position to progress towards clinical trails in the next phase of work. This will involve producing demonstrator APRICOTs for the other hands in the joint, building up a regulatory file and a business case, and performing a first in human clinical trial.
While a lot of the work in this project has had to be protected due to its very novel nature, the research institutes have been able to disseminate in their specialist areas, and to date, they have achieved 7 peer reviewed journal publications in open access journals with further publications in preparation, 10 international conference presentations, conducted extensive outreach activities, and developed a strong social media presence. Significant IP has been generated by the lead industrial partner to ensure the technology is protected as we progress it to clinical use.
A project website was created and regularly populated with new information. The communication, dissemination, and exploitation strategy was refined, and Key Exploitable Results established. A Project Management Platform was constructed to assist with the management of the project.
Over the two remaining reporting periods, surface treatments and fixation techniques were developed that enabled the implant to function as intended, that is, with very low friction while retaining its position in the joint. Biocompatibility testing of the surface treated and untreated implant materials showed that the materials were tolerated in vivo. Mechanical testing on artificial bones showed that the implant was able to function efficiently for over one million loading cycles. Once the concept was proven in the laboratory, cadaver trials were undertaken at two centres. These trials demonstrated the effectiveness of the APRICOT implant, highlighting its ultra-low invasiveness, its ability to remain in place and supported by the surrounding soft tissue, and its ability to restore the full kinematic function of the joint over a wide range of flexion/extension angles and with smooth, almost frictionless movement. An unexpected benefit of the device was the very short surgery time.
At project conclusion, the consortium achieved the objective of proving the APRICOT concept in two ways: (i) via testing in the lab under long term repeated loading in artificial bone joints, and (ii) via testing in cadaver joints to demonstrate the restoration of full joint function. The cadaver tests illustrated that the implantation was simple, rapid (< 10 minutes), and involved little to no trauma. These very encouraging results place the project in a suitable position to progress towards clinical trails in the next phase of work. This will involve producing demonstrator APRICOTs for the other hands in the joint, building up a regulatory file and a business case, and performing a first in human clinical trial.
While a lot of the work in this project has had to be protected due to its very novel nature, the research institutes have been able to disseminate in their specialist areas, and to date, they have achieved 7 peer reviewed journal publications in open access journals with further publications in preparation, 10 international conference presentations, conducted extensive outreach activities, and developed a strong social media presence. Significant IP has been generated by the lead industrial partner to ensure the technology is protected as we progress it to clinical use.
The APRICOT implant goes beyond the state-of-the-art by obviating the need for (i) bone removal and (ii) two solid components articulating against each other (enabling minimally invasive implantation), and allowing for (iii) the creation of cartilage like friction and damping capabilities and (iv) natural range of motion and kinematics. It creates a paradigm shift in the way OA of small joints is treated by replicating the functionality of cartilage using a novel design principle based on caterpillar track movement. This motion prevents sliding movement at the anatomical surfaces, thus preventing wear at the implant site. As articulation occurs within the implant through an ultra-low friction mechanism, in the unlikely event that wear debris is generated, it will be retained within the sac. To realise the unique geometry of the APRICOT, novel thermoforming techniques have been developed for the first time. Unique, bespoke testing rigs and test protocols have also been developed to prove the robustness of the device. Ultimately, the APRICOT will restore mobility without the need to remove healthy bone, and will avoid the need to subject the (often frail) patients to general anaesthetics and traumatic operating procedures.
The project has addressed critical limitations in the treatment of osteoarthritis by creating a highly original, risky, but potentially very high gain solution that has the potential to place Europe at the forefront of small joint arthroplasty.
The project has addressed critical limitations in the treatment of osteoarthritis by creating a highly original, risky, but potentially very high gain solution that has the potential to place Europe at the forefront of small joint arthroplasty.