Patent ID: 7867281
Filing Date: 2011-01-11
Classification: A61F,A61L

Abstract:
1. A hip prosthesis comprising: a spherical bearing member, said spherical bearing member having a neck recess therein, a femoral stem, said femoral stem having a recess adjacent a proximal end thereof, a modular neck member, a proximal end of said modular neck member configured to fixedly engage said neck recess of said spherical bearing member, a distal end of said modular neck member configured to fixedly engage said recess of said stem, an acetabular implant having a concave bearing surface configured for articulation with said spherical bearing member, wherein one of said spherical bearing member and said concave bearing surface comprises a soft metal bearing surface of cobalt chrome alloy, said soft metal bearing surface having a hardness of at least about 20 Rc, and wherein said other one of said spherical bearing member and said concave bearing surface comprises a hard metal bearing surface of cobalt chrome alloy, said hard metal bearing surface having a hardness greater than said soft metal bearing surface by at least about 15 Rc, such that there is a hardness differential between said spherical member and said concave bearing surface to thereby reduce wear of said hip prosthesis.