A method of expanding an expandable spinal interbody fusion device, in situ, includes the steps of providing an expandable spinal interbody fusion device having an elevator disposed between relatively movable inferior and superior endplates, the elevator being captively supported for movement along a direction of expansion independently of movement of the inferior and superior endplates, releasably attaching a distal end of an inserter to the device, the inserter including an actuator at a proximal end thereof, and operating the actuator to cause the elevator to move toward the superior endplate and move the superior endplate away from said inferior endplate to expand said device.