Principles, techniques, results, and complications with a porous-coated sintered metal system.

Experience with biologic fixation hip arthroplasty using the powder-made sintered porous system has been very encouraging over the past 8 years. With simple implant design, accurate instrumentation, and careful attention to surgical technique, the results of surgery can be made equal to those obtained with conventional cemented arthroplasty (using the current improved implant designs and cementing techniques). Most of the problems associated with this new technology have been recognized and solved. The most serious problem is probably that of stress shielding and disuse osteoporosis, and this may well be overcome through judicious design modification. It is the next decade that will determine whether the incidence of late aseptic loosening is reduced through design for a "living" interface between implant and bone.