Hip Arthroplasty Has a Long History

since late 1930s--varieties of materials tried--faliures in bonding and fracture

The Charnley Total Hip Is the Standard

figured out to use a metal base with a plastic cup

Techincal Problems Limit Implant Longevity

losening and disintigration of the contact surfaces

Implant Materials Have Evolved

alumina-on-alumnia is ideal but you have to get tolerances of 15 to 40 microns or it fails catastrophicaly

Modifications in Use of Cement Reduce the Rate of Failure

Computers and Robots are Coming into Use