Patent ID: 7909877

Claim:
A movable disc implant, comprising: a first engaging plate for engaging a first surface of a disc space between two vertebral bodies in a spine, wherein said first engaging plate has a first edge, a convex portion, a first inner surface between said first edge and said convex portion, a second edge, a second inner surface between said second edge and said convex portion, and an outer surface, wherein said first inner surface and said second inner surface are sloped relative to said outer surface of said first engaging plate, and wherein said convex portion is a semi-cylindrical portion having a length extending in a first direction parallel to the first edge and an arcuate cross-sectional shape in a plane perpendicular to the first direction; a first member having a projection extending in a second direction perpendicular to the first direction, a recess extending along the first direction, a third inner surface and a fourth inner surface, wherein said recess of said first member complements said semi-cylindrical portion of said convex portion of said first engaging plate, wherein said first member and said first engaging plate are positioned such that said convex portion of said first engaging plate at least partially fits in said recess of said first member, said third inner surface of said first member faces said first inner surface of said first engaging plate and said fourth inner surface of said first member faces said second inner surface of said first engaging plate to allow said first member to rock relative to said first engaging plate about an axis parallel to said first direction; a second member having a recess and a convex portion, wherein said recess of said second member complements said projection of said first member, wherein said convex portion of said second member is a semi-cylindrical portion having a length extending in a third direction perpendicular to the second direction and an arcuate cross-sectional shape in an anteroposterior plane, and wherein said second member has an axis of rotation parallel to the second direction about said projection of said first member, wherein the third direction is perpendicular to the first direction when the implant is in an un-rotated orientation; and a second engaging plate for engaging a second surface of said disc space, wherein said second engaging plate has a recess extending in the third direction having an arcuate cross-sectional shape in an anteroposterior plane that complements said convex portion of said second member.