Patent ID: 7780738

Claim:
An implantable articulating bone prosthesis, comprising: a first component having an articulation surface formed from a biocompatible doped silicon nitride ceramic having a flexural strength greater than about 700 Mega-Pascal (MPa) and a toughness greater than about 7 Mega-Pascal root meter (MPam 0.5 ), wherein said doped silicon nitride comprises one or more dopants selected from the group consisting of yttrium oxide, magnesium oxide, strontium oxide, and alumina; and a second component having an articulation surface formed from a biocompatible polymer which is not a ceramic, wherein said first component and said second component are shaped for a joint prosthesis and one of said articulation surfaces of said first component and said second component has a generally concave shape and the other of said articulation surfaces of said first component and said second component has a generally convex shape.