Try using a back marker over it and wiping off the excess. The marker should then be left in the indentations and make it show up.
From what you've described it looks like the catalogue number for the implant and the SS is for Stainless Steel which just means it's the surgical variety ENJ58 stainless steel.
Has your hip been xrayed? Do you have a copy or can you get a copy of that? You could photograph that. A prosthesis can often be ID from the xray.
Are you hoping to get the same implant or something? If it's being replaced, then I would imagine that after all this time, they'll replace the whole thing. Of course it depends why it's being redone - is it for loosening or wear?