Novel tendon attachment and repair strategy

Every year there are >3,000people that injure their hand tendons. Currently, only 60% of these people result with an effective repair. This is because scar tissue forms that is not the same as its original tissue, making the hand stiff and difficult to move properly. This poor healing not only has an impact on the person with the injury, but also on the NHS as physiotherapy and occupational therapy costs post injury as a result are high. This project proposes an exciting and novel approach to repairing tendons. It allows mechanical loads to be transferred across the healing tendon which will promote new healthy tissue repair and reduce the formation of scars. We have a currently funded DPFS grant that has given us a promising set of data that demonstrates how state of the art polymer nano-fibres can be used in tendon repair. This data is in small rodents only and we now seek further MRC DPFS funding to perform larger animal model studies to translate this product development to the clinic. The proposed multidisiplinary research team have international track records in the area of clinical tendon repair, biomaterials development and medicinal product translation. In this project, this team will gather the regulatory data necessary on this novel medical device read for clinical trial following this project.

Tendons are susceptible to injury and their repair remains an unmet clinical need as only 60% achieve a satisfactory functional result. The UK incidence of flexor tendon injuries is >3,000 patients per annum, many of whom have multiple tendon injuries. Currently, there are inadequate surgical procedures for injured tendon; repair involves the formation of scar tissue which is biochemically and biomechanically inferior to natural tendon tissue. Tendon injuries can be severely disabling, with significant rehabilitation time and high healthcare costs. Our approach represents a paradigm shift with a novel device delivered by keyhole surgery. It also enables the transfer of load across different parts of the device as the tendon heals so that physiotherapy starts earlier and scar tissue formation is reduced.

Our current DPFS project has characterised novel PCL electrospun scaffolds and generated compelling in-vivo data in short and long term small animal studies. The PCL fibres have demonstrated tendon repair in the rat model and through clinician-led design/FEA modelling techniques we have identified a novel concept for a medical device. We seek continued MRC support, to develop and demonstrate performance in larger animal studies and readiness for clinical evaluation. The team has the necessary expertise in biology, engineering and clinical practice and with MRC support the device will be developed for clinical readiness and commercialisation. A critical pathway to partnering the technology with an industrial partner for future clinical development has been defined through direct engagement, and will be achieved by the commercial, regulatory and design expertise included in the project team. A key aim of the project is to work with end users of the device to gain their feedback and guidance on the requirements of the product which drive both the commercialisation and clinical pathway for the research and development ultimately leading to improved patient outcomes.

Economic Impact
Tendons are susceptible to injury and their repair remains an unmet clinical need as only 60% achieve a satisfactory functional result. The UK incidence of flexor tendon injuries is >3,000 patients per annum, many of whom have multiple tendon injuries. Currently, there are inadequate surgical procedures for injured tendon; repair involves the formation of scar tissue which is biochemically and biomechanically inferior to natural tendon tissue. Tendon injuries can be severely disabling, with significant rehabilitation time and high healthcare costs.
Across the UK this device would be applicable to Orthopaedic surgeons (>700), plastic surgeons (300), specialist hand surgeons (300) and hand therapists are all end users. The UK incidence of hand flexor tendon injuries is >3,000 patients per annum, many of whom have multiple tendon injuries each requiring individual repair. The number of sports injuries, e.g. Achilles tendon injuries and shoulder tendon injuries, are also increasing.
The deliverable on this project, a tendon repair and attachment device suitable for hand surgery, would provide a platform for a suite of future products adapted to tendon types. The device would have scope for worldwide usage and business planning would incorporate the opportuntiy to provide this device on a global scale, particularly in the EU and US markets.
This device would benefit these end users by reducing 1) the proportion of patients with poor outcomes, 2) the current burden of re-operation; and 3) the high level of patient management and follow-up required post-surgery. The current 3-month period of very limited mobilisation post-surgery has changed little over many years and compares very poorly with innovations in other areas of surgery, for example hip replacement patients can now weight bear within 12 hours of surgery and heart transplant patients can mobilise a week post operation. The opportunity to use multiple devices according to the size of tendon injured also provides the surgeons with flexibility and the device can be used in both Trauma and elective surgery.

Physiotherapists' rehabilitation programmes are determined by the tensile strength of the repair over the time course of the patient's recovery, so new physiotherapy routines will also be introduced allowing earlier mobilisation.
The patients themselves are the ultimate end users and beneficiary. Their overall rehabilitation time could be shortened by 50% allowing a quicker return to driving, work and mobility. Reduced follow up and re-operation costs will benefit the NHS and other health providers.

Knowledge and Scientific Impact
This project would bring together a highly skilled and experienced team to deliver this project to ensure the aim of gaining the necessary data to proceed to a clinical trial.
The novel approach adopted to tendon repair would highlight a paradigm shift in the way damaged tendons are repaired; whilst sufficient mechanical strength is key to repair, the focus on our approach is to assess the biological response to tendon damage and direct this to promote faster, stronger tissue growth.
Additionally, the route to regulatory compliance for tendon repair has been challenging due to no defined consistent approach in the scaling of a product through animal testing models.
The project's primary objective is to gain the necessary data in order for a full clinical trial to commence following this next phase of funding. To achieve this, we need to standardise manufacturing processes, understand the biological response of the device in situ, and comply with regulations to ensure a full and appropriate data package at project end.