Implants: An object lesson in Ineffectiveness

Via the NY Times, an Australian study shows how newer models of joint prostheses fail at higher rates then older more established models.  The failure rate may not be the worst aspect of the newer style implants.  They also pose risks due to breakdown of the metal rubbing on metal, releasing metallic particles into surrounding tissue.  Resulting inflammation can make replacement surgery "far more complex and can leave some patients with lasting complications."  Some questions:

• What drove physicians to use the newer implant style over the old one?
• What disclosure was made to patients about the relative risks?
• Do we really not keep an implant registry?  Getting information second hand from Australia is the best we can do?