An interbody system for implanting between vertebrae, the interbody system comprises a cage having a cage body that includes a graft chamber having a volume that receives graft material, a sagittal wall that forms a portion of the graft chamber, and a wall membrane that forms another portion of the graft chamber. The interbody system may comprise an interbody device that includes an aperture that receives a bone fastener, wherein the wall membrane interacts with the bone fastener. The wall membrane may bend as result of a force applied by the bone fastener to a portion of the wall membrane, thereby providing directional support to the bone fastener and/or forcing graft material from the graft chamber.