Patent ID: 8512406

Claim:
A device positionable in a spinal column between endplates of first and second vertebrae, comprising: a first member including a body extending from a first end surface for engaging an endplate of the first vertebra to an opposite second end surface, said body of said first member extending around at least one chamber and said at least one chamber opens at said first and second end surfaces, said at least one chamber comprising a middle chamber and a pair of end chambers on opposite sides of said middle chamber, each of said end chambers being separated from said middle chamber by a wall; and a second member including a body extending along a longitudinal axis between a first end surface and an opposite second end surface, said second end surface of said first member positioned in contact with said first end surface of said second member, wherein said second member includes at least one engaging member extending along said longitudinal axis away from said first end surface of said second member and at least two extensions extending along said longitudinal axis away from said first end surface of said second member, each of said at least two extensions being parallel relative to one another and being equidistant from said at least one engaging member, said at least two extensions comprising a first extension positioned in one of said pair of end chambers and a second extension positioned in the other of said pair of end chambers, said at least two extensions contacting said body of said first member at opposite sides of said body to resist rotation of said first member relative to said second member about said longitudinal axis and said at least one engaging member being positioned in said middle chamber and in contact with said body of said first member to resist displacement of said first member away from said second member along said longitudinal axis.