US Patent 7540882 Artificial spinal fusion implant with asymmetrical leading end

An interbody spinal implant made of a material other than bone adapted for placement across an intervertebral space formed across the height of a disc space between two adjacent vertebral bodies. The implant has a leading end that includes at least a portion of an arc of a circle from side to side, and sides that are at least in part straight or a trailing end having a radius of curvature of another circle from side to side.