A device for facilitating bone fusion of two vertebrae. The device is sized and shaped to at least extend between the two vertebrae to be fused, and includes an outer wall member disposed about an inner portion. A space between the outer wall member and the inner compartment is adapted to contain an osteogenic bone fusion material. The inner portion includes a compartment adapted to contain an inner fill material, such as a bone cement or an in situ curable polymer. The inner portion may operate as a structural member to maintain a desired amount of spacing between the vertebrae to be fused, and to support the spinal column prior to formation of the fused bone joint. The device is also configured to locate the osteogenic material away from the centers of the vertebrae to be fused, providing a fused joint with high bending and torsional rigidity.