Abstract: An intervertebral spacer in the form of a generally flat four sided disc, with two opposite sides having slightly curved surfaces and two opposite sides having pointed lobes. The disc is configured to be placed between two vertebrae and rotated, with the rotation spreading the vertebrae and moving the pointed lobes into contact with the inner vertebral faces, for holding the vertebrae a fixed distance apart.

Abstract: An intervertebral spacer in the form of a generally flat four sided disc, with two opposite sides having slightly curved surfaces and two opposite sides having pointed lobes. The disc is configured to be placed between two vertebrae and rotated, with the rotation spreading the vertebrae and moving the pointed lobes into contact with the inner vertebral faces, for holding the vertebrae a fixed distance apart.

Abstract: The invention is a bone screw apparatus. The bone screw apparatus has two specialized functions for stabilizing the screw within a bone. The first is a mechanical structure that anchors the screw within a bone and the second is a structure that allows injection of bone cement through the screw assembly and into the interior structure of the bone. The anchoring mechanism functions by an expandable member that slides concentrically over the shaft of the screw. When the expandable member is forced over a portion of the screw shaft with an enlarged diameter, the expandable member extends radially from the screw shaft, and the bone screw is anchored to the interior structure of the bone. The injecting function of the bone screw apparatus functions through the use of a hollow core within the screw shaft. The hollow core of the screw shaft has an inlet at the top of the shaft and at least one outlet near the tip of the screw shaft.

Abstract: The invention is a bone screw apparatus. The bone screw apparatus has two specialized functions for stabilizing the screw within a bone. The first is a mechanical structure that anchors the screw within a bone and the second is a structure that allows injection of bone cement through the screw assembly and into the interior structure of the bone. The anchoring mechanism functions by an expandable member that slides concentrically over the shaft of the screw. When the expandable member is forced over a portion of the screw shaft with an enlarged diameter, the expandable member extends radially from the screw shaft, and the bone screw is anchored to the interior structure of the bone. The injecting function of the bone screw apparatus functions through the use of a hollow core within the screw shaft. The hollow core of the screw shaft has an inlet at the top of the shaft and at least one outlet near the tip of the screw shaft.