Patent ID: 8016889

Claim:
An articulating prosthetic spinal implant for implantation between vertebrae in a human body, the implant comprising: a first endplate having a first side attachable to a spine bone and having a second side, a first body of solid, sintered polycrystalline diamond, said first body of diamond being received within a recess on the second side of the first endplate, a sintered polycrystalline diamond protrusion on said first body, a protrusion load bearing and articulation surface located on said protrusion, said protrusion having a curvature defined by at least one radius R 1 , a second endplate having a first side attachable to a spine bone and having a second side, a second body of solid, sintered polycrystalline diamond, said second body of diamond being received within a recess on the second side of the second endplate, a sintered polycrystalline diamond receptacle on said second body, a receptacle load bearing and articulation surface located on said receptacle, said receptacle having a curvature defined by at least one radius R 2 , a solvent-catalyst metal located in said sintered polycrystalline diamond, diamond to solvent-catalyst metal bonds between said diamond and said solvent-catalyst metal in said sintered polycrystalline diamond, a gradient transition zone in said sintered polycrystalline diamond, said protrusion and said receptacle being sized and curved to accommodate said protrusion protruding into said receptacle, and to accommodate said protrusion load bearing and articulation surface contacting said receptacle load bearing and articulation surface, said contact of said protrusion with said receptacle being accomplished by diamond to diamond contact of said protrusion and receptacle load bearing and articulation surfaces, said contact of said protrusion with said receptacle occurring at a diamond to diamond contact point where diamond of said protrusion contacts diamond of said receptacle, said diamond to diamond contact resulting in diamond on diamond articulation between said protrusion and said receptacle, said protrusion being translationally movable with respect to said receptacle in the axial plan of a human spine, said translational movement being accomplished by a sliding or rolling movement of diamond against diamond; wherein R 1 and R 2 are chosen to accommodate said translational movement; and wherein at least some of said translational movement occurs in the axial plane of a human spine about an arc of a circle having a radius R 3 whose center is located at the base of the spinal process of a human spine, and wherein R 3 is not equal to R 1 or R 2 .