Hip Implant Testing

Following surgery, proximal loosening and stress shielding can occur as a result of normal activity and can lead to abnormal loading profiles. Therefore, the real-life environment and loads that the specimen will experience while in the body need to be replicated in testing. Hip femoral fatigue testing can be challenging due to the importance of precisely embedding the specimen. The fixture needs to be capable of supporting compression, bending, and torsional stresses in order to meet ISO 7206 standards. The high-frequency rates of these tests also pose a challenge as they can cause the specimen to heat up beyond an acceptable limit.

Instron® provides a specimen embedding device that ensures the required offset angles and embedding depth is achieved. The purpose-built corrosion resistant fixture allows for in vivo testing. The assembly comes complete with a temperature controller and a recirculating pump to ensure the temperature never exceeds the acceptable limit by automatically reducing the frequency of the test. The easy-to-install fixture includes a low-friction loading head and adapters for mounting it to an ElectroPuls™ system. The Instron WaveMatrix™ software allows a number of test-end criteria to be used, such as running a specific number of cycles or until specimen fail is detected, which can be determined in a number of ways. With one package you can confidently test to and exceed the requirements for ISO 7206-4, 7206-6, and 7206-8.