One of the keys to a successful implant is its ability to withstand the rigors of daily activity, and central to that is the quality of the artificial surfaces that slide against each other, or articulate, in the new joint.
In knee implants, bearing surface options have been somewhat limited over the last few decades. The standard substance used for the femoral component is cobalt chrome, a metal alloy typified by its tough¬ness and biocompatibility. However, even this high-quality industry standard has its shortcomings. Over time, this metal surface can become roughened by bone and bone cement particles trapped between the femoral component and the plastic tibial insert.
This roughened surface, when rubbing against the plastic component up to two million times per year, can more quickly wear out your implant. When that happens, you will have to undergo surgery to replace the plastic piece, the femoral compo¬nent, and possibly even the tibial component. For this reason, implants have been shown to last between 10 and 15 years in the human body.
The most exciting material to enter orthopaedics in recent years is OXINIUM° (oxi¬dized zirconium.)This remarkable new material combines the strengths of ceramic and metal, such as wear-reduction and strength, but does not have the weakness¬es, such as limited implant options and the possibility of fracture.
Zirconium is a biocompatible metal, similar to titanium. When the zirconium alloy undergoes a unique heating process, the surface of the metal transforms into a ceramic. Even though the new ceramic surface is 4,900 times more abrasion resistant than cobalt chrome, it retains the toughness and flexibility of the underlying metal.
Because it can achieve this remarkable reduction in implant wear without sacri¬ficing strength as actual ceramic com¬ponents do, OXINIUM° implants have the potential to last significantly longer, thus possibly reducing the need for future corrective surgeries. When articulating on standard plastic tibial components, OXINIUM° knee implants reduce wear by 85-percent compared to cobalt chrome.