Patent ID: 8277508

Claim:
An intervertebral disc prosthesis for implantation between first and second vertebral endplates, the prosthesis comprising: a first endplate assembly for engaging the first vertebral endplate, the first endplate assembly having a concave first inner surface and having a first outer edge with a lip extending partially downward past the first inner surface; a second endplate assembly for engaging the second vertebral endplate, the second endplate assembly having a concave second inner surface and having a second outer edge with a lip extending partially upward past the second inner surface; and a core component extending between the first and second inner surfaces and adapted to move relative to the concave first and second inner surfaces, wherein the core component includes, a flexible body fixedly attached between first and second end surfaces having convexly curved outer surfaces configured to mate with and engage the concave first and second inner surfaces and having respective first and second outer edges, the end surfaces being discrete from one another, wherein the flexible body includes a convexly curved outer wall and the first and second end surfaces have outer perimeters that do not extend past the outer wall and wherein the first end surface of the core component includes a peripheral groove shaped to receive and interlockingly connect with a peripheral ridge formed in the flexible body of the core component and wherein the first and second end surfaces have a hardness greater than the flexible body; and the flexible body includes a first continuous straight surface that faces outward towards and contacts the first end surface and an opposing second continuous straight surface that faces outward towards and contacts the second end surface wherein the first outer edge of the first endplate assembly extends past and below and at least partially engages the first outer edge of the first end surface and the second outer edge of the second endplate assembly extends past and up and at least partially engages the second outer edge of the second end surface.