Abstract: A dynamic fusion device for facilitating arthrodesis in a disc space between adjacent vertebrae that includes a body and an engaging member. The body extends along a longitudinal axis having a first portion and two or more legs depending from the first portion. The legs are laterally spaced apart from each other and define a second end of the body spaced opposite the first end. The legs define an engaging member receiving cavity. An engaging member, such as a disc, is secured to the body and received within the engaging member receiving cavity, wherein the engaging member is secured to the body only by engagement of the engaging member with the legs. During installation, the engaging member causes the legs to flex.