HC series servo-hydraulic testing machines
On the one hand, dynamic loading on the hip endoprosthesis stem while walking with an implant that is already loosening is simulated in order to check the stem life expectancy. On the other hand, alternating loading is applied to the neck region of the prosthesis, which is clinically well-anchored. Zwick software allows you to run user-friendly progressive load tests (Locati tests).
These tests can be implemented under physiological environmental conditions (for example, temperature-conditioned saline solution) with the use of the Zwick temperature conditioning vessel. This enables you to perform a corrosion test to ASTM F1875, which tests a modular junction's resistance to crevice corrosion and fretting corrosion under dynamic load.
Determination of endurance properties of stemmed femoral components
A minimum of six hip endoprosthesis stems must withstand 5 million load cycles with a maximum load of 2300 N and a minimum load of 300 N.
Determination of endurance properties of head and neck region of stemmed femoral components
A minimum of six hip endoprosthesis stems must withstand 10 million load cycles at a load of 5.34 kN (R=0.1).
Endurance performance of stemmed femoral components with application of torsion
Lever out test
Lever-out testing on hip joint pairings
Artificial hip joints must withstand both compressive loads and torsion loads. To determine the optimum materials and alloys, these are tested with a special testing machine,
consisting of a 20-kN Zwick materials testing machine plus a 500-Nm torsion drive.
The artificial hip joint (here made of metal) is rotated on a support unit (torsion loading) and compression loading is applied at the same time. This tests materials and alloys best suited for artificial hip joints.