Patent ID: 8906096

Claim:
An intervertebral disc prosthesis for installation in a spinal column, comprising: a first intervertebral plate for engaging one or both of the inferior vertebral endplate and the inferior ring apophysis of a superior vertebral body; a second intervertebral plate for engaging one or both of the superior vertebral endplate and the superior ring apophysis of an inferior vertebral body; a removable insert core located between and engaging the intervertebral plates, the removable insert core having a first upper surface and a second lower surface, and when the removable insert core is installed, the first upper surface contacts the first intervertebral plate and the second lower surface contacts the second intervertebral plate; and a projection that projects from one of said intervertebral plates toward the other one of said intervertebral plates, wherein the projection extends at least an entire height of the removable insert core and into an aperture formed in the other one of the said intervertebral plates, wherein the aperture is sized and dimensioned to receive at least a portion of the projection, wherein the removable insert core directly engages the projection when installed, and wherein the removable insert core is removable from between the intervertebral plates and from around the projection while the intervertebral plates and projection remain installed.