a multi - piece disc replacement implant device for replacing a disc removed by a discectomy including an upper plate member , a lower plate member , and an intermediate resilient member providing movement between the two plate members replicating the natural movement of the spine including flexion / extension , lateral bending , and , in some embodiments , rotation . the plate members are rigid and have orthogonal sidewalls forming an enclosure . the resilient member is an elastic solid or a multi - chamber balloon structure of fluid - filled sacks that collectively define a non - uniform shape such as an oblate spheroid , or a helically coiled string of beads . such an implant is capable of supporting the compressive and cyclic loads required of a natural disc . the upper and lower plate members are cooperatively formed to selectively limit the allowable range of motion in any given direction . alternate embodiments of the invention may be employed in conjunction with removal of the nucleus pulposus when removal of the annulus fibrosus is not required or desirable .