Zero-profile expandable intervertebral spacer devices for distraction and spinal fusion and a universal tool for their placement and expansion

An expandible intervertebral fusion device comprising:

• a first movable body;
• a second movable body;
• and
• means for moving the first movable body with respect to the second movable body to expand a dimension of the expandible intervertebral fusion device,
• wherein the first movable body includes:
• a top wall, a bottom wall, and two sidewalls defining an open space capable of receiving bone filling for the biological bone fusion;
• and
• an internal screw guide having an entry opening and an exit opening, the entry opening formed only in a top surface of the top wall and the exit opening formed at least partially in a bottom surface of the top wall and at least partially in a side surface of the top wall.

An expandible intervertebral fusion device comprising:

• a first movable portion;
• a second movable portion;
• and
• a mechanism that moves the first movable portion and the second movable portion with respect to each other to expand a dimension of the expandible intervertebral fusion device,
• wherein the first movable portion includes a first top wall, a first bottom wall, a first sidewall, and a second sidewall defining a first open space capable of receiving bone filling for the biological bone fusion, wherein the second movable portion includes a second top wall, a second bottom wall, a third sidewall, and a fourth sidewall defining a second open space capable of receiving bone filling for the biological bone fusion,
• wherein the first top wall of the first moveable portion and the second top wall of the second moveable portion cooperate to form a top wall of the expandible intervertebral fusion device,
• wherein the first movable portion includes a first internal screw guide having an entry opening and an exit opening, the entry opening formed entirely between all edges of a top surface of the first top wall when viewed from a direction perpendicular to a plane of the top surface of the first top wall and the exit opening formed at least partially in a bottom surface of the first top wall and at least partially in a side surface of the first top wall, and
• wherein the second movable portion includes a second internal screw guide having an entry opening and an exit opening, the entry opening formed entirely between all edges of a top surface of the second top wall when viewed from a direction perpendicular to a plane of the top surface of the second top wall and the exit opening formed at least partially in a bottom surface of the second top wall and at least partially in a side surface of the second top wall.