Abstract: A vertebral cage is provided for use in preserving the space between adjacent vertebral during the process of spinal fusion. In particular, this cage has an open modified oval peripheral shape with a continuous fluid anterior wall having angled screw passages accessible through co-planar openings to allow the construct to be stabilized between adjacent vertebral bodies through their endwalls. In addition, the cage has a back to front wedge taper with pull-out resistant ratchet surfaces. Further, in a second aspect of the invention, the screw passages have a unique locking mechanism provided by oversized internal threads in combination with a second locking thread on the head of the associated bone screws that allows for axial translation of the screws within the screw passages. This in turn permits play in the angulation of the screw relative to the anchoring bone in order to optimize the screw placement in the bone.

Abstract: A vertebral cage is provided for use in preserving the space between adjacent vertebral during the process of spinal fusion. In particular, this cage has an open modified oval peripheral shape with a continuous fluid anterior wall having angled screw passages accessible through co-planar openings to allow the construct to be stabilized between adjacent vertebral bodies through their endwalls. In addition, the cage has a back to front wedge taper with pull-out resistant ratchet surfaces. Further, in a second aspect of the invention, the screw passages have a unique locking mechanism provided by oversized internal threads in combination with a second locking thread on the head of the associated bone screws that allows for axial translation of the screws within the screw passages. This in turn permits play in the angulation of the screw relative to the anchoring bone in order to optimize the screw placement in the bone.