A mobile cage system for restoring motion kinematics of the spine featuring a pair of opposing caps that form a cavity and a nucleus disposed in the cavity. The system allows for motion of the caps relative to the nucleus. The mobile cage system provides sufficient support so as to eliminate the need for incorporation of a metal plate or rod and pedicle screws that may be used for spinal fusions. The mobile cage system of the present invention also prevents vertical collapse of the vertebrae and complete bone fusion, and the mobile cage system helps preserve intervertebral motion of the spine.