The present invention provides a fusion cage comprising a first housing, a second housing, and an alignment portion adapted to be received between the first and second housings such that the first and second housings are held in place by said alignment portion. The alignment portion can be varied in shape such that the fusion cage is wedge-like in shaped, or slanted to one side. Further, the alignment portion is constructed of a radiolucent material to allow for visualization of a bone fusion within the fusion cage.