A conglomerate of homologous bone-chips and n-butyl-cyanoacrylate fixes the fragments in the ultrasonic osteosynthesis. The sound pressure leads to the forced penetration of the monomer into preformed gaps of the bone surface (Volkmann and Haversian canals) up to maximum 300 microns during the polymerisation forced by ultrasound. A toothing effect between the conglomerate and the cortex takes place in this way, this one leads to a higher mechanical resistance and to specialities in the regenerative process. The term welding is founded scientifically by the mechanism of the connecting formation. On the other hand the application of the ultrasound is sensible in order to force the polymerisation.