US Patent 9078767 Expandable spinal interbody fusion device

An expandable spinal interbody fusion device comprises an inferior endplate having an outer surface configured to contact a vertebral body of the spine and a superior endplate having an outer surface configured to contact an opposing vertebral body. The inferior endplate and the superior endplate are movable relative to each other in a direction of expansion. The device includes an elevator captively supported between the inferior endplate and the superior endplate for independent movement along the direction of expansion. In the first direction the elevator is moved toward said superior endplate to lift the superior endplate and expand the device. In the second direction the elevator moves away from said superior endplate toward said inferior endplate to create a space for insertion of an insert into the expanded device.