Hip replacement xray

3D-printing advanced bone-integrating implants

The increase in life expectancy, despite being one of the greatest achievements in human history, poses a challenge to our healthcare system in the form of increasing age-related medical conditions. The upward trend in numbers of hip and knee replacements performed is one part of this challenge. Researchers at the University of Liverpool are 3D printing these implants with innovative surface structures, resulting in improved long-term performance compared to conventionally manufactured designs.

The challenge

Over 2,500,000 procedures are carried out around the world annually to alleviate the suffering caused by disease or injury to a joint. In England and Wales more than 160,000 hip and knee replacement procedures are performed each year.

Joint replacement is usually a successful procedure, but a significant number of implants must be replaced because of loosening of the implant from the living bone. This not only causes considerable pain and limits the patient’s life, but also increases pressure on healthcare service resources due to higher numbers of revision surgeries.

Research action

Over the last 15 years, world-class and pioneering research led by Professor Chris Sutcliffe at the University of Liverpool has developed, patented and licensed a 3D-printed porous metal implant to counter this loosening.

The unique porous design allows bone to grow naturally into the implant forming a strong biological interlock. The technique also allows the implants to be custom-shaped to practically any geometry, so the implant can be adjusted to fit the patient. The developed 3D printing technique, called L-PBF (laser powder bed fusion), utilises high-power industrial lasers and metal powders to manufacture the unique porous implants.

Working in partnership

This global research project brought together engineers and scientists from the UK, Europe and the US, making the technology a scientific, engineering and commercial success. Close collaboration from the start of the project with global leaders in orthopaedic implant manufacturing allowed the work to gain early momentum, from being one of 20 competing technologies to one of two deployed in production.

Years of collaboration have resulted in global patents, PhD studentships and infrastructure development of at the university and the company Renishaw. The initial funding for the project was gained from Renishaw and EPSRC.

Professor Sutcliffe has been active in manufacturing research since 1997 and has led multiple ESPRC, Innovate UK and EU-funded projects. He is the director of the University spin-off company Fusion Implants, formed by engineers and veterinary surgeons from the University of Liverpool.

Outputs and outcomes

The 3D-printed implants and the unique manufacturing technique have been patented, licensed, up-scaled and commercialised. The implants have already helped hundreds of thousands of patients around the world, reaching over 300,000 new patients every year. The innovative design is increasing implant lifetime and reducing revision surgery rates, improving the quality of patients’ lives, reducing costs for healthcare providers and freeing up resources for other treatments.

The technique Sutcliffe and colleagues developed now forms the global backbone of industrial 3D printing for metals. The research collaboration is also accelerating novel implant designs and investigating new ways to produce the materials, and the newly established additive manufacturing facility is now employing over 100 highly-skilled engineers and scientists.

Research leader Professor Sutcliffe was awarded the Royal Academy of Engineering Silver Medal in 2018.

A fully developed, patented and licensed technique for 3D-printing porous metal implants can improve patient outcomes and reduce the need for further surgery.

Professor Chris Sutcliffe

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