Well, I resisted replying to this thread for 10 days, but it keeps popping up and tempting me. I looked long and hard at Smith & Nephew's technology prior to my knee replacements. What Smith & Nephew calls its "Verilast" technology was introduced in the USA three years ago in the spring of 2010 and is a marriage of S & N's proprietary femoral component called "Oxinium" with a "highly cross linked poly" spacer.
The femoral component is made of an oxidized zirconium which forms a ceramic surface of a few millimeters (meant microns) and has been available in the USA for over a decade. S & N has long touted the superior wear characteristics of its proprietary femoral material. Highly cross linked poly spacers have been used by many firms also publicizing its wearing abilities.
Putting both of these together, along with extensive, successful ex-vivo testing, lead the FDA to approve S & N to market (in the USA) this product as a "30 Year Knee." I don't think this product is warrantied in the USA. If my post-TKR primary goal was to do ultradistance cycling, I might very well have chosen a top notch surgeon using this product.