A methodology for grafting together adjacent bony structures is provided using an implant device having an endplate with an inner disc portion and outer ring portion spaced from the inner disc portion by a connecting wall disposed therebetween. An endplate interior surface includes a retaining structure for securing the endplate to one of the bony structures, and endplate an exterior surface has an integrally formed socket. A ball-joint rod has a longitudinally extending body and an end, and at least a portion of the ball-joint rod end is curvilinear in shape. The curvilinear ball-joint rod end is rotatably disposed in the endplate socket to fixedly interconnect the bony structures.