Spinal implant

A method of installing an intervertebral disc prosthesis in a spinal column, comprising:

• inserting an intervertebral disc prosthesis into a disc space, the intervertebral disc prosthesis including:
• a first intervertebral plate for engaging one or both of an inferior vertebral endplate, and
• a second intervertebral plate for engaging one or both of a superior vertebral endplate,
• a gap located between the first and second intervertebral plates, and
• a projection that projects from one of said intervertebral plates toward the other one of said intervertebral plates, wherein the projection extends 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;
• inserting a removable insert core in the gap between the first and second intervertebral plates, the removable insert core having a first upper surface that contacts the first intervertebral plate and a second lower surface that contacts the second intervertebral plate;
• and
• removing the removable insert core while the intervertebral plates remain installed in the disc space, wherein the projection maintains proper spacing between the intervertebral plates while the insert core is removed.

A method of installing an intervertebral disc prosthesis in a spinal column, comprising:

• inserting an intervertebral disc prosthesis into a disc space, the intervertebral disc prosthesis including:
• a first intervertebral plate for engaging one or both of an inferior vertebral endplate and an inferior ring apophysis of a superior vertebral body,
• a second intervertebral plate for engaging one or both of a superior vertebral endplate and a superior ring apophysis of an inferior vertebral body,
• a removable insert core positioned between the first and second intervertebral plates, the removable insert core having a first upper surface that contacts the first intervertebral plate and a second lower surface that 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;
• and
• removing the removable insert core while the first and second intervertebral plates remain installed in the disc space.