First and second bone segments separated by a fracture line or joint can be fixated or fused by creating an insertion path through the first bone segment, through the fracture line or joint, and into the second bone segment. An anchor body is introduced through the insertion path. The distal end of the anchor body is anchored in the interior region of the second bone segment. An elongated implant structure is passed over the anchor body to span the fracture line or joint between the bone segments. The proximal end of the anchor body is anchored to an exterior region of the first bone segment to place, in concert with the anchored distal end, the anchor body in compression, to thereby compress and fixate the bone segments relative to the fracture line or joint. A bony in-growth or through-growth region on the implant structure accelerates the fixation or fusion of the first and second bone segments held in compression and fixated by the anchor body.