ABSTRACT
To this purpose, and trying to replicate the expected in-vivo condition, the Standard suggests to test the stem as follows: i) it must be embedded in a cement mantle – the cement elasticity being comparable with that of surgical bone cement – up to a pre-defined distance D from the centre of the head which corresponds to 80mm for stems in the range (120 to 250) mm; ii) stem adduction angle α must be set to 10◦, stem flexion angle β to 9◦, and a rotation equal to the eventual anti-version angle must be performed before cementing the stem; iii) a sinusoidal load in the range (300 to 2300) N must be applied with a frequency in the range (1 to 30) Hz. The fatigue test has to be continued until the deflection of the head exceeds 5mm, or fracture of the specimen occurs, or the maximum number of requested cycles (5× 106 cycles) is reached.
