Development of Metal/Metal Hip Resurfacing

Abstract

This author's development of metal/metal hip resurfacing began in 1989, with the first patient implantation in February 1991. In the first three years a pilot study identified optimum fixation as hydroxyapatite coated uncemented cups and cemented femoral components. From March 1994 hybrid fixed components have been used. These implants have generally been satisfactory with respect to fixation but high wear of the bearing, metallosis and osteolysis have been seen with some components inserted during 1996, a period during which the metal microstructure was altered by the heat processes, hot isostatic pressing and solution heat treatment. The Birmingham Hip Resurfacing was developed taking account of experience with earlier resurfacing designs. This implant employs hybrid fixation with a porous ingrowth acetabular component and has an as-cast metal microstructure having had no post casting heat treatments. During the past 4 years the author has performed over 1,000 Birmingham Hip Resurfacingís with a total failure rate of less than 1.0%.