A screw implant a shaft and a threaded area for anchoring in the bone, a head having engagement surfaces or openings for the application of an insertion tool, wherein the shaft and the head are formed in one piece, wherein there is associated with the shaft between the thread and the head at least one separation area where the head with an upper part of the shaft is separated, and a replacement head, which can be fixed to the remaining lower part of the shaft. The replacement head may have an inner drill hole, which is from the size designated to fit a cross section of the shaft and into which the shaft is inserted.
