Patients in Merseyside get revolutionary Oxinium Knee

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

Mrs Linda Wood, a 49 year-old voluntary playgroup leader from Liverpool, received one of the first Oxinium knee implants in the UK, after suffering with increasing chronic pain in her left knee for almost 20 years. The initial problem occurred when she was knocked down by a car at the age of 8 years and sustained a broken kneecap. Mrs Wood said, “My knee was so painful before I had the operation in February last year, that I could not walk up the stairs normally. My new knee has meant that I can live my life now. I have the same problem in my right knee, but I am so convinced by this knee replacement that Mr Davidson plans to operate on my right knee early next year.”

More than 46,000 knee replacement operations are carried out every year in the UK, 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 John Davidson, FRCS, an orthopaedic surgeon at Liverpool and Broadgreen University Hospitals is a pioneer in using Oxinium implants, having performed over 100 Oxinium total knee replacement operations. 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. Oxinium is 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.” Mr Davidson is one of the UK’s leading experts on knee replacement surgery, and for these uses 60% Oxinium knee replacements, mainly in the younger population.

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 Merseyside area with several local surgeons starting to use this newer material.

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 do not 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 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 an industry-defining technology,” said Jonathan Houghton, Knee Product 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. The benefits of Oxinium are now also available as femoral heads for total hip replacement, meaning that the younger or more active patient may have the opportunity of a hip replacement that could last their lifetime due to its superior strength and endurance.”