Patent ID: 7122055

Claim:
An intervertebral spacer device, comprising: first and second plates, said plates being disposed in a spaced apart relationship such that a plate surface of said first plate faces a plate surface of said second plate, said facing surfaces being inner surfaces, and alternative faces of each plate being outer surfaces; and at least one restoring force providing element disposed between the inner surfaces of said first and second plates, and disposed such that a compressive load applied to the outer surfaces of said first and second plates is counteracted by said at least one restoring force providing element, said at least one restoring force providing element including at least one spider spring having a central hub and a plurality of spring arms extending radially from the central hub, wherein one of said first plate and said at least one spider spring comprises a curvate socket and the other of said first plate and said at least one spider spring comprises a semispherical protuberance that is rotatably and angulatably couplable to the curvate socket, wherein the semispherical protrusion comprises a radially deflectable semispherical portion and the curvate socket has an interior volume and an opening leading to the interior volume, the curvate socket accommodating the semispherical portion for free rotation and angulation therein, the semispherical portion fitting through the opening only when radially deflected, the semispherical portion being adapted to receive a deflection preventing element that when applied to the semispherical portion prevents the semispherical portion from fitting through the opening, wherein the semispherical protuberance comprises at least one radial slot such that the semispherical protuberance is radially deflectable upon the application of a radially inwardly directed force.