ISO 7206-4:Implants for surgery - Partial and total hip joint prostheses -- Part 4: Determination of endurance properties and performance of stemmed femoral components
ISO 7206-6: Implants for surgery -- Partial and total hip joint prostheses -- Part 6: Endurance properties testing and performance requirements of neck region of stemmed femoral components
PI-58 (ISO 7206-8): Implants for surgery -- Partial and total hip joint prostheses -- Part 8: Endurance performance of stemmed femoral components
The fatigue test according to ISO 7206-4 simulates the dynamic loading of a hip stem during gait. Proximal loosening of the stem is presumed to simulate worst case conditions. Load inclination as well as the embedding level is described by ISO 7206-4. PI-58 (ISO 7206-8) describes the load levels required as well as the minimum number of cycles.
ISO 7206-6 simulates a well ingrown stem. The critical part from the mechanical point of view is the neck region of the stem.
The maximum test frequency depends on the flexibility of the stem and the performance of the test equipment. EndoLab® developed special tools to embed the stem correctly (s. Fig.) that ensures constant loading of the implant. Most of our tests are performed using MTS equipment.