Adjustable interbody fusion device and method of use

An expansion mechanism for moving a first member relative to a second member, the expansion mechanism comprising:

• a cylindrical gear sized to rest within an opening, the opening positioned within the first member;
• a threaded rod having a pivot cylinder on a first end, wherein the threaded rod comprises a plurality of external threads extending along the length of the threaded rod;
• a load head having a top surface and a bottom surface, wherein the load head is configured to couple and move relative to the threaded rod;
• a drive rod, wherein the drive rod is configured for insertion into an adjustment opening of the first member to engage the cylindrical gear, wherein the drive rod comprises:
• a cylindrical shaft with a first end and a second end;
• worm gear at the first end;
• a tool opening at the second end;
• and
• a channel in the cylindrical shaft positioned between the first end and the second end;
• and
• a locking mechanism, wherein the locking mechanism is configured to engage an adjustment opening in the first member and the tool opening in the drive rod, the locking mechanism comprising:
• a head including an opening for engaging an insertion tool and a plurality of protrusions configured to engage the adjustment opening;
• and
• a shaft extending away from the head and configured to engage the tool opening in the drive rod.

A method of using an interbody fusion device, comprising:

• obtaining an interbody fusion device, wherein the interbody fusion devices comprises
• a base member comprising a first end, a second end, a first bone contacting surface, a first inner surface opposite the first bone contacting surface, and at least one projection extending from the first inner surface along a first end portion of the base member forming a pivot cylinder, wherein the pivot cylinder is fixed to the first inner surface;
• a top member comprising a first end, a second end, a second bone contacting surface, and a second inner surface opposite the second bone contacting surface including a hinge channel extending along a first end portion of the top member, wherein the pivot cylinder is configured to engage the hinge channel to enable the hinge channel to pivot on and about the pivot cylinder;
• and
• an expansion mechanism for moving the top member relative to the base member to cause the top member to pivot relative to the base member on and about the pivot cylinder
• making an incision to expose a first vertebral body and a second vertebral body of a patient's spine;
• preparing a space between the first vertebral body and the second vertebral body for receiving the interbody fusion device;
• obtaining an insertion tool, the insertion tool comprising:
• a handle;
• an insertion end;
• at least one tube extending away from the handle and connecting the handle and the insertion end;
• a first knob configured to couple to the handle;
• and
• an actuation bar moveable between a first position and a second position to enable the first knob to engage an adjustment mechanism in the first position and a securement mechanism in the second position;
• inserting the insertion tool into an opening in the base member and coupling the insertion tool to the interbody fusion device;
• inserting the interbody fusion device into the space between the first vertebral body and the second vertebral body;
• rotating the insertion tool to move the top member relative to the base member:
• uncoupling the insertion tool from the interbody fusion device;
• and
• closing the incision.