Following surgery, proximal loosening and stress shielding can occur as a result of normal activity and can lead to abnormal loading profiles. Fatigue testing
of hip implants is used to determine the endurance properties by simulating the dynamic loading of the implant during gait.
ISO standards have been established to test for both abnormal and normal fatigue loading.
- ISO 7206-4: simulates loading when proximal loosening has occurred. Loads are applied through the femoral head of the hip implant to induce compressive, bending and torsional stresses.
- ISO 7206-6: examines fatigue of the implant neck, which is more consistent with a correctly fixed implant subjected to normal in vivo loading.
- ISO 7206-8: specifies the endurance performance of the implant with the application of torsion
Our Femoral Fatigue Fixture was designed to meet and exceed the requirements of the ISO tests. The fixture includes a low-friction loading head and adapters for mounting to either a 8872 fatigue testing system and or an ElectroPuls™ All-Electric Dynamic Test Instrument. The fixture can also be easily adapted to suit other testing machines and test setups. The flexible specimen holder accommodates a wide variety of hip geometries, offset angles, embedding materials, and embedding depths. Specimens are potted into the holder using an optional embedding fixture to maintain alignment during the potting process.
Additionally, the fixture accommodates a small environmental chamber for complete in vivo simulation.