A spinal cage includes a first support plate pivotally connected to a second support plate by a hinge, and a plate mover actuated by an actuator and located between the first and second support plates. The plate mover is arranged to slide against an inclined surface on the first support plate. A hinge is journaled in an elongate aperture formed in a hinge housing protruding from first support plate, the hinge being free to translate and rotate in the elongate aperture.
