Patent attributes
A bone screw implant is provided for immobilizing the articular surfaces of two bone segments by securing, fusing, or compression the two segments. The implant may be fabricated from a porous biocompatible metal and have a cylindrical shape and fully or partially threaded and may have variable pitch threads and a variable diameter of the shaft. The implant may include a blunt tip or a fluted self-drilling tip and a headless screwdriver socket. Large pitch cancellous threads may be in the leading-end portion of the cylinder shaft, and smaller pitch cortical threads may be at the trailing edge portion of the shaft. The implant may be fenestrated, it may have a roughened surface, and it may be coated with an osteoconductive material. The implant may be cannulated. In a specific embodiment, the implant is used for immobilizing the articular surfaces of a sacroiliac joint.