Patent ID: 7105024

Claim:
An artificial intervertebral disc comprising: housing members including spaced inner surfaces facing each other and oppositely facing outer surfaces for engaging spaced apart intervertebral surfaces; bearing means extending from each of said inner surfaces for engaging each other while allowing for low friction and compression resistance relative to each other while under compression; load sharing means disposed between said inner surfaces and about at least a portion of said bearing means for sharing absorption of compressive loads with said bearing means while limiting the relative movement of said housing members, said bearing means including a concave surface portion extending from one of said inner surfaces and a convex surface portion extending from the other of said inner surfaces and seated against said concave surface portion for sliding movement relative thereto effectively resulting in relative pivoting motion of said housing members which can compress at least a portion of said load sharing means while distending at least a portion of said load bearing means, the load sharing means being elastic for allowing relative twisting movement between said housing members effecting relative three dimensional movement between said housing members while limiting the movement and preventing contact between the housing members except for the bearing means; a pair of disc members, each of said disc members including one of said bearing means, said inner surfaces of said housing members including disc seating means for seating one of said disc members therein in opposing relationship of the other of said disc members seated in said seating means of the other of said housing members, said disc seating means including a pocket recessed into each of said inner surfaces of said housing members; and locking means for selectively preventing relative movement of said disc members and said housing members once each disc member is seated in its respective pocket, said locking means for each disc member comprising at least one undercut groove disposed about one of said pocket and said radial periphery of the disc member, and at least one flange disposed about the other of said pocket and said radial periphery of the disc member for locking engagement with said undercut groove.