Patent ID: 7621957

Claim:
An intervertebral spacer device comprising: a member constructed of a porous material with pore sizes ranging from 100 to 500 microns, the member having a top surface, a bottom surface, a side surface, and at least one hole extending from the side surface through the member to and through one of the top or bottom surfaces, the at least one hole including a continuous taper that extends fully through the spacer forming a larger diameter at the side surface and a smaller diameter at the one of the top or bottom surfaces; at least one screw including a semi-spherical head; and at least one coupling element including a semi-spherical interior volume with a width that is larger at an interior than at either opposing ends and a continuous exterior taper that reduces in width from a top side to a bottom side, the at least one coupling element mountable to the semi-spherical head of the at least one screw such that the at least one screw and the at least one coupling element are rotatable relative to each other, the at least one screw insertable into the at least one hole such that the at least one coupling element is lockable within the at least one hole, the at least one coupling element responsive to compressive loads between the screw and the member to cause the at least one coupling element to frictionally engage the semi-spherical head of the at least one screw and lock the at least one screw in the at least one hole, wherein the at least one coupling element includes a slot, the slot extending an axial length of the at least one coupling element such that the at least one coupling element has an incomplete periphery.