[Shear fracture stress of the spongiosa and pressure fracture stress of cortical bone of cadaveric vertebrae].

By biomechanic examinations of the vertebrae of human dead bodies the ultimate stress due to shearing (Schubbruchspannung) of the spongy substance could be found out with 1.80 N/mm2 and the ultimate stress due to compression (Druckbruchspannung) of the cortical-belonging to the thick of cortical--with 280 N/mm2. Both measuring results are important for the ultimate strength of the connection (Verankerungsfestigkeit) of screws in vertebae.