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Each year an estimated 1,324,000 artificial knee joints (total knee replacements — TKR) are implanted worldwide; an estimated third of these utilise an implant manufactured by DePuy International. Underlying computer-based research performed by the Bioengineering Sciences Research Group has played a central role during the development of a new design of TKR for DePuy. The design programme, the biggest in DePuy's history, had a budget in excess of US$10 million and aimed to replace the existing TKR system, which had annual sales of approximately US$100 million.
Between 2007-2010, DePuy adopted the computational techniques developed by the group as screening tools to (i) assess polyethylene wear and (ii) account for the effects of surgical variability during the early design phases. DePuy states "This research allowed us to choose the most robust solution when proceeding to mechanical testing and saved years in the design cycle. Patients also benefit from increased confidence in an implant that is able to withstand the rigors of use".
The University of Southampton's world-leading record in bioengineering continues to deliver significant benefits, resulting from recent research crucial to the development, pre-clinical verification and CE-marking of a revolutionary hip-resurfacing implant. In the wake of growing concerns over some previous implant designs, this work has positively impacted on a wide range of audiences: over 9800 patients have received the new implants with excellent early clinical results at two years' follow-up. Within 4 years UK PLC benefited with considerable additional turnover [exact figure removed for publication], a majority from abroad, and the technology attracted three years of investment for a start-up company at Southampton Science Park. This award-winning knowledge transferring research has been widely acknowledged as an example of best practice, and has increased appreciation of science and technology further through outreach.
Surface wear in moving components can endanger human lives and costs the UK economy £24 billion every year. Excellent research in this area — known as Tribology — at the University of Southampton (UoS) led to the foundation of the national Centre of Advanced Tribology (nCATS), which collaborates with over 100 companies and institutions in many sectors. Examples of nCATS impact include research findings forming an integral part of a BNFL/Sellafield Ltd's design guide for the prevention of radioactive slurry leakage. It also enhanced GE Aviation's competitive advantage by supplying novel electrostatic wear debris sensors (the only system in use), which have been integrated into new fighter aircraft engines.
Long-term fixation integrity is a critical issue in joint replacement surgery that affects both quality of life of patients and the economy. The unique comprehensive study of long-term acetabular cement fixation carried out at the University of Portsmouth has significantly informed orthopaedic surgeons and impacted on their surgical practice. In addition, research on a commercial hydrogel implant TRUFIT has informed clinical and commercial decisions on the use of the implant for load bearing applications, which has led to the withdrawal of the implant from the global market.
Over 100,000 hip joint replacements are performed each year in the UK. The correct restoration of joint centre is critical to the successful outcome of total hip replacements. Failure to do so results in dislocation, increased wear and leg length discrepancy.
In collaboration with QUB, over 4,000 patient-specific custom hip prostheses were manufactured and implanted at Musgrave Park Hospital, Belfast, leading to accurate restoration of anatomical joint centre.
As a consequence a new surgical instrument has been developed and utilised in more than 4,000 surgeries. Surgical costs are reduced compared to the alternative of computer-aided surgery. The DePuy Synthes Companies are funding the development of a later version of this surgical instrument
The high failure rate of metal-on-metal hip implants led to worldwide concern. Collaborative research between Newcastle University and University Hospital of North Tees identified design features that are considered to have contributed to the failure. The research helped to inform policy makers both nationally, such as the Medicines and Healthcare products Regulatory Agency (MHRA), and internationally, such as the US Food and Drug Administration (FDA). The final outcome was a worldwide withdrawal of one design of implant (the DePuy ASR) and a ban in several countries of a set of implants sharing common features (large head metal-on-metal total hip replacements). The research has reduced the risk of harm to patients who will now receive products with a significantly lower failure rate, and will have financial implications for implant manufacturers and healthcare providers.
Research into the field of metal-on-metal (MoM) arthroplasty (joint replacement) conducted at the University of Bristol in conjunction with the National Joint Registry of England and Wales (NJR) has led to a fundamental change in the practice of arthroplasty around the world and in the clinical follow up of patients. High failure rates have been identified nationally in England and Wales for MoM total hip arthroplasty and certain designs of resurfacing arthroplasty in work conducted by our department. Deleterious systemic effects of wear debris produced by these implants have also been identified by our research. The use of these devices has declined from 14% of procedures in 2008 to less than 1% in 2012. Citing our research, national bodies including NICE (2014), the MHRA (2011 & 2012), the UK Department of Health (2012), British Orthopaedic Association (2011 & 2012), NJR (2012), British Hip Society (2011 & 2012) and the US Food and Drug Administration (FDA) (2013) have issued guidance suggesting the restricted use of such devices or close surveillance of patients in whom these devices have been implanted.
Our research has developed improved hip replacement fixation techniques, which have improved the biomechanical stability of implanted artificial joints. These techniques have been employed by orthopaedic surgeons, for example at Mid-Essex Hospitals Services Trust (MEHT), in primary and revision total hip replacement operations. As a result, the number of patients requiring revision hip surgery due to cup loosening has fallen by 50%. Additionally, these techniques have reduced the recovery time per operation by 3-5 days, which in addition to benefitting the patient have also resulted in an average saving per operation of £1,200.
Research at University of Oxford led to the development of the Phase 3 Oxford Knee in 1998, a significantly improved and less invasive knee replacement, allowing implantation through a small incision. Due to its many advantages over other knee replacements, including faster recovery, fewer complications and better function, the Phase 3 Oxford Knee is now the most widely used partial knee replacement in the world. Approximately 1 million people have benefitted from this development.
This case concerns the impact of research carried out at the Durham Centre for Biomedical Engineering on compliant layer lubricated artificial joints, which mimic natural human joints and have been used by a commercial company (Active Implants, USA) to develop specific products namely "TriboFit" and "NUsurface" conservative hip and knee replacement systems. Our underpinning technology has allowed them to produce a successful range of products. To date 1300 patients in Europe, Israel and Australia have received the "TriboFit" devices and about 90 patients are taking part in a $10M clinical trial on the "NUsurface" artificial meniscus for the knee.