An improved method of fusing the sacroiliac joint and tools for accomplishing the same is disclosed. In one embodiment, the present invention is a method that uses an intra-articular joint fusion device for connecting the sacrum and ilium that includes creating a first incision in the patient's skin proximal to the patient's sacroiliac joint, inserting a surgical channel tool into the incision from the patient's posterior, creating a void in the sacroiliac joint, inserting a fusion implant into the void, the fusion implant having at least one fixation element for engagement with bone tissue in the articular surfaces of the sacrum and the ilium, and driving the fusion implant into the void such that the at least one fixation element engages with bone tissue in an articular surface of at least one of the sacrum and ilium, and the fusion implant fixes relative positions of the sacrum and ilium.
