I live in UK and have recently been having same concerns.  I am 47 and posted the "age of first TKR and multiple revisions" entry.

I was contacted by someone who has had the Smith & Nephew Oxinium in Liverpool who recommended it, and I have found a consultant in London who uses that knee so it is available over here!

In my case the consultant has decided to do a further debridement and to try and burr away some of the oestophytes, hoping to delay the replacement a few more years as I have a little space still on the medial side.  However it is inevitable that I will have the replacement as the lateral side is bone on bone, and the Oxinium certainly seems the best option from the research I have done.  The problem with the cobalt ones is there limited life compared to the Zirconium ones. 

I am going in for the arthrotomy next week and hope it will delay the inevitable at least two years!

Neil

Good post ,I w ill be 49 this fall and really concerned about having this done at this age because I'am really active . Don't get me wrong my knees hurt al lthe time and have losss tremendous range of motion , probably could not survive without anti inflammatories , as a matter of fact . So I want to have this done to get rid of arthritis pain and fixe the old cowboy bow legs but fear wearing em out. Have any of ypou heard about the new oxidized zirconium knee replacements ? They cost 9500 more but are supposed to last 20 -25 years ?

My OS was going to use the oxidized one but Zimmer came out with a new "zirconium coated" one.  Actuallt I don't think it is coated like icing but bonded with titanium.  Any way he likes Zimmer the best.  I got it because I have a nickel allergy and all the replacement that  have cobalt have a small % of nickel in them.  He thinks this "new knee" last longer because the surface is so much smoother and there will be less friction.  The cobalt/chrome joints wear on the plastic disk and that is what has to be replaced.