Patent ID: 8100977

Claim:
A modular disc prosthesis that is adapted to be implanted in an evacuated disc nucleus space from a generally posterior approach, the prosthesis comprising: at least three modular segments, each modular segment having a width defined by opposing sides, a proximal end, and a distal end, the modular segments being selectively interlockable with each other such that the prosthesis has: an extended configuration in which the proximal end of one side of an outer modular segment is operably positioned proximate the distal end of one of the sides of an intermediate modular segment and the distal end of one side of another outer modular segment is operably positioned proximate the proximal end of another of the sides of an intermediate modular segment, and an implanted configuration in which the modular segments are positioned within the evacuated disc nucleus space in a generally side by side relation with the proximal ends of each modular segment adjacent one another and the distal ends of each modular segment adjacent one another so as to define a unitary body having a generally continuous periphery in which an overall width of the modular segments generally corresponds to a width of the evacuated disc nucleus space, wherein each modular segment comprises an outer shell of a layer of solid polymer material having a depth extending outward from an inner core, the inner core of each modular segment having a durometer hardness higher than a durometer hardness of the outer shell of each modular segment, the inner core of each modular segment including structure on at least one side that selectively interlocks with corresponding structure on at least one side of an adjacent modular segment, the outer shell substantially surrounding the inner core of each modular segment except for the at least one side having the structure that selectively interlocks adjacent modular segment.