Knee Replacement
Components Made from
BIOLOX®delta Ceramics
The number of knee joint replacement operations done each year is continually
increasing. The current worldwide estimate is roughly half a million.
Globally, knee replacement is the second most frequently performed joint
replacement after hip replacement. The life expectancy of the population as
a whole is greater now than ever before and the desire for greater mobility
and improved quality of life after knee replacement has also increased.
Furthermore, the incidence of knee replacement in young and active patients
is also increasing. Consequently a longer implant lifetime for knee
replacement prostheses is required. For this reason, particular importance
must be attached to the choice of implant material, especially with respect
to the biological behaviour and wear properties of the selected material.
The single most important problem is wear
Knee replacement implants are usually made from either cobalt chromium alloy or titanium alloy. The wear surfaces are normally cobalt chromium alloy in combination with polyethylene. Clinical evidence and long term results show that aseptic loosening limits implant lifetime. One of the most important causes of aseptic loosening is the wear of plastic components made of polyethylene. As demonstrated in many investigations, an increased rate of polyethylene wear can lead to an increased rate of loosening as a result of the formation of granuloma and foreign-body reactions with associated destruction of bone stock. In the literature it has also been suggested that immunological and allergic responses to metallic elements (cobalt, chromium and nickel) contained in the alloys used in metallic implants are also a possible cause of aseptic loosening and post-operative complications such as delayed wound-healing and skin reactions.
New ceramics provide advances in knee replacement surgery
In collaboration with international orthopaedic companies CeramTec AG has set itself the goal of increasing significantly the life of artificial knee joints by reducing the wear rate and the risk of allergic response. To this end, BIOLOX®delta ceramics offer an optimal solution, thanks to their mechanical properties, their wear-resistance and their excellent biocompatibility. In addition, BIOLOX®delta ceramics do not cause allergic reactions.
Market Launch of Ceramic Knee Joint Replacements
Ceramic knee joint replacements components will be entering the market soon. The first clinical use of ceramic knee joints is expected at the end of 2005. The short term results of these implantations will be reported at the forth-coming 11th BIOLOX® Symposium, which will take place in Rome on June 30 and July 1, 2006. We will keep you informed on this and other matters in the "Current Topics" area on our Medical Products Division's entry page.