ASTM F2722 Mobile Bearing torque test

The test described in ASTM F2722 relates exclusively to knee endoprosthesis systems with mobile bearings and restrictions of internal and external rotation. The femoral and tibial components are fixed to the test device, with the femur component having the maximum permissible flexion angle and the mobile bearing being placed between the two components. Under a constant axial load of 2,000 N and a cycle number of 220,000, the mechanical properties of the knee endoprosthesis system under internal and external torsional loading (14 Nm) is evaluated.

The torsion test is not carried out with mobile bearings, which allow a rotation above ±20°.