Katie, Bryan and Prestige LP are titanium. Newer prestige is titanium and ceramic.
JKDE302, more secure only matters if less secure is a problem. I don't think that more smaller keels are necessarily more secure... it will likely depend upon how much surface area interfaces with the bone. We talk about primary and secondary fixation. Primary fixation is the 'stay puttedness' of the device upon implantation. Secondary fixation occurs after osteointegration of bone and the coating on the prosthesis. After osteointegration, migration is unlikely even in the 'no keel, no cleats' design (PCM). PCM has a double whammy of poor primary fixation AND the large radius joint surface that does not keep everything centered. I believe that the clinical trials were halted because of migration. (This is what I was told by a surgeon in the trial. I do not have any documentation about this.... I consider it a rumor, but because of the source, I trust it.)
Migration or expulsion of the prosthesis has been seen in all devices, but I've never seen it ever, ever, ever; with properly implanted devices. I'd rather have a well placed PCM than a poorly placed ProDisc or other device... even though the device factors should be discussed, understood and considered... IMHO, the choice of surgeon is far more important.
Mark
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