Abstract: A method for fusing a spinal sacroiliac joint The method includes the steps of locating the sacroiliac joint, retracting the soft tissue to expose the graft site, removing any bone obstructions and preparing a relatively smooth graft site horizontal to the immediate sacroiliac joint, creating a therapeutic cavity by creating a first cavity in the ilium and a second cavity in the sacrum to a predetermined depth that spans the sacroiliac joint, inserting a stabilization implant into the therapeutic cavity, and seating the implant within the therapeutic cavity at a predetermined depth.