Systems, methods and devices for spinal fusion are disclosed. In particular, certain disclosed embodiments are configured to permit the addition of lordosis to a spinal fusion cage after implantation through the use of various expansion mechanisms to spread arms of the spinal fusion cage. Disclosed embodiments may include the use of a threaded wedge to expand the arms, the use of a keel within a series of detents, the use of supplemental fixation screws, and the use of a rotating cam.