The present invention relates to an apparatus for the strictly limited flexible stabilization of long bone fractures, said apparatus incorporating a stabilization element configured to be a helical rod that may be introduced into the cavity of a long bone and that comprises a fixation device at one end at least. In accordance with the invention there is provided that the helical rod comprises, beside a very high vertical spring rate, a bending spring rate that is reduced to the “physiological” level as compared to a marrow nail so that, once placed in the bone, minimal healing-promoting movements are being stimulated. It is further preferred that the helical rod has a normalized, uniformly configured head that is independent of the variable outer diameter of the helical rod, which is adapted to the respective bone. Since the head is configured to be uniform and normalized, a uniform tool can be utilized for screwing the rod in, irrespective of the size (diameter) of the helical rod respectively used during surgery. It is also possible to apply the tool in the head region in order to screw the helical spring out again.
