Also see
http://pictures.doccheck.com/en/photos/323/14839/synovialitis-due-to-titanium-abrasions-of-the-acetabulum-after-tep-of-the-right-hip/
Or http://pictures.doccheck.com/en/photos/323/1795/tep-keramikkopf-zerstoert-titan-pfanne-mit-inlay2/?cide=