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Derby's racing car engineer, David Whitehurst, benefits from knee replacement technology that he uses in car engines

June 11, 2003

Derby's and Nottingham's younger population to benefit from state-of-the art knee replacements that offer up to 85% improvement in wear and tear over standard knee implants

The active, younger population of Derby and Nottingham, like David Whitehurst, who suffer from arthritis or chronic injury can now benefit from knee replacement surgery much earlier in life due to new implant technology, called Oxinium™, which has recently been made available to everyone in the UK after 11 years of tests.

Mr David Whitehurst, a 60-year-old engineer from Derby, whose knees had degenerated after an injury from a car accident back in the 1960s, received one of the first Oxinium knee implants in the UK, said "As an engineer I know the importance of maintaining smooth, long-wearing moving parts, and for this reason use the same ceramic component that is in my knee replacement in the engines of racing cars.   It is interesting that this ceramic is also used in jet engines because it is an excellent heat conductor, and can withstand huge amounts of pressure and friction. It doesn't surprise me that the Oxinium knee made it possible for me to have surgery at a younger age than a traditional implant would allow because it is so hard wearing. I'm doing really well and have been able to get on with my life, enjoying working again, driving and walking around with no pain at all since the surgery. In fact this new knee works better than my healthy normal knee."

More than 30,000 knee replacement operations are carried out every year in the UK and over 700 of these in the Derby/Notts region alone, with an increasing number carried out on people under the age of 60. Orthopaedic surgeons have traditionally delayed joint replacement surgery in patients younger than 60 because they do not expect the materials used to withstand the wear placed on them for longer than 10 to 15 years. Replacing the knee the second and third time is much harder and much less likely to succeed.

Mr Timothy Wilton, a leading orthopaedic surgeon at Nuffield Hospital Derby and the Derby Royal Infirmary and a pioneer in using Oxinium implants performed David Whitehurst's operation. He comments, "This knee replacement addresses one of the most critical issues in orthopaedics today, namely that the lower the amount of wear, the longer the implant will last. The second issue is the brittle nature of standard ceramic components which can occasionally break, but with Oxinium there is no brittleness. We now have a superior implant that is expected to last longer and will allow active, younger patients to benefit much earlier from a replacement knee. This in turn will reduce the amount of suffering a patient often experiences due to a painful knee."

British company Smith & Nephew developed this new metallic alloy in response to the orthopaedic community's concerns over wear and tear of current implants. After 11 years of development and biomechanical testing, the Oxinium knee implants are now widely available to patients in the Derby and Nottingham area.

Currently, most knee implants are made from a cobalt-chrome alloy that slides against a plastic (polyethylene) bearing. The motion and friction caused by daily living can damage the implant's surface and cause metal and polyethylene wear debris, ultimately causing bone loss and the need for another implant.

Various metals, including titanium, have been used for implants and provide strength but don't address the issue of wear. Knee implants made of ceramics may reduce wear but are brittle and can crack. Because Oxinium components are made of a metallic zirconium alloy that is heated to convert the surface to a ceramic the best of both worlds can be achieved. Compared to cobalt chrome, Oxidized Zirconium, in knee wear simulation testing, reduced the rate of polyethylene wear by 85 per cent.
      
Oxinium will give younger or more active knee replacement candidates an alternative to waiting for knee replacement in discomfort and immobility until doctors decide they are more age-appropriate for a traditional implant.

Nickel sensitive patients also benefit
Oxinium is the first implant to contain non-detectable traces of nickel, providing a solution for patients identified as acutely allergic to this metal. Up to 8% of the population suffers with nickel allergy, and for the first time can now be offered a knee replacement, where previously few alternatives were available to them.
      
"We believe that this is going to be an industry-defining technology," said Mark Withers, Sales and Marketing Manager, Reconstruction, Smith & Nephew. "It's really a testament to what can happen when the industry listens to surgeons and seeks to find completely new and innovative solutions to their clinical issues. We feel confident that Oxinium will have an enormous impact on young patients suffering pain and disability from arthritis whose quality of life at the moment is severely impaired by the limitations of currently available technology. There are also plans to extend the Oxinium benefits to total hip replacement where the benefit to this specific patient group could be even greater."

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