If these materials behave in vivo as they do in vitro and if no unexpected complications occur, periprosthetic osteolysis should be reduced, the duration of THR success should be greater, and the percentage of complications should be lower. Femoral loosening, socket loosening, and pelvic and femoral lysis should be reduced. There should be fewer revisions and dislocations and a greater range of motion. [Table: see text] If these improvements come to pass, use of the new materials may be an important advance in THR surgery.