A composite interbody device includes (a) a plastic core having a superior surface and an inferior surface, (b) a superior endplate and (c) an inferior endplate. Each of the superior and inferior endplates includes (i) a bone interface side for interfacing with bone and having a plurality of pores permitting bone growth therein, and (ii) a core interface side, opposite the bone interface side, having a plurality of voids that accommodate material of the plastic core to couple the endplate to a respective one of the superior and inferior surfaces, wherein the voids are isolated from the pores to prevent the material of the plastic core from entering the pores.
