The present invention comprises a method of stabilizing adjacent vertebral bodies with an expandable and size varying spinal fusion intervertebral implant device that comprises an expandable top(s) and, or bottom. The method comprises inserting the device into the intervertebral disc space. Once properly positioned, the method further comprises engaging the expandable body of the device by inserting and rotating a screw that runs along the longitudinal axis of the implant.The expansion of the hinged top(s) and, or bottom may be used to restore normal balance, tilt and disc height of the vertebrae. Further, expansion of the device will engage surrounding vertebrae, thereby securely seating the device within the intervertebral disc space.The method further comprises providing a bone material in or on the expandable cutting body of the device and, or in or on the intervertebral spacer portion of the device to permit fusion of the adjacent intervertebral bodies.
