Also you're right Redhead about the reasons for surgeons not using stainless in prostesis, but there's another reason... they use plastic when possible because it's lower impact, and titanium vs stainless because it has an even lower oxidation/corrosion rate than any steel aswell as being either almost or completely (I'm not sure off the top of my head which) non-magnetic, which means it causes much less of a problem with things like airports *smiles*