ISO 7206-4

Fatigue Test ISO 7206-4

ISO 7206-4 is the standard test method for hip joint implants, used to determine the endurance properties of both stemmed femoral components used individually in a partial hip joint replacement or the stemmed femoral components of total hip joint prostheses. The goal of yielding measurements is to ensure that the prosthesis will not fail or break in its lifetime.

Testing conditions should provide an environment that mimics in vivo. Stress shielding and proximal loosening occur from regular activity after surgery, leading to a patient’s abnormal loading profiles. Stemmed femoral components that are used for partial and total hip joint prostheses are used to help support loading activity and profiles.

Femoral components of total hip joint prostheses are assessed with Fatigue Test ISO 7206-4, which simulates dynamic loading on a device during gait, thereby measuring performance and endurance. ISO 7206-4 is a component of ISO 7206: a set of standards chosen and grouped together because of behavioral congruency between the implants used in clinical settings for transfemoral amputations and total or partial hip replacement.

ISO 7206-4 Testing Methods

Within ISO 7206-4 testing guidelines, environmental conditions are defined, as well as specimen testing set-up methodology to ensure all components are performed with the utmost consideration for all variables. Primary concerns are the specimen’s support levels, load application angle selection, testing frequency, and environmental aspects.

Cyclic Load Simulations

ISO 7206-4 testing includes axial loading simulation in the event of proximal loosening. Axial loading is simulated through the hip implant’s femoral head to induce compressive, bending, and torsional stresses. Tests usually run up to five million cycles and have to adhere to the 2,300 N load required by ISO 7206-4. It’s one of the most critical aspects of this fatigue testing method, as it measures endurance properties at the peak load applied to the stemmed femoral components.

ISO 7206-4 Testing Conditions

Testing conditions stipulated by ISO 7206-4 are designed to facilitate valid predictions of stemmed femoral components’ in vivo performance. The specimen is first embedded in solid material, such as acrylic bone cement. This serves to mimic bone support loss, which is the compound concern that results in total catastrophic failure.

ISO 7206-4 testing conditions include a test fluid solution of sodium chloride deionized or distilled in grade 3 water for modular specimen analysis in wear study. The batch size required for these tests is currently determined at six specimens.

Through the use of these testing methods, durability and design optimization are incentivized. Should any problems be found, alterations to coatings, surface finish, or manufacturing may be the culprit that must be adjusted.

Working with Empirical Technologies

If you are looking to submit a product to the FDA for approval that needs ISO 7206-4 testing, Empirical Technologies is here to lend expertise and help you accomplish that goal. We have a trusted track record of experience and a team of medical device testing experts who understand the nuance and technical specifications required to conduct tests according to every last detail.
With deep understanding and experience in ISO 7206-4 testing, we are confident that we can deliver accurate and comprehensive endurance properties of stemmed femoral components. Contact us today to request an estimate or to learn more about how partnering with us will streamline your product launch.
Please refer to the ISO website for the most up to date information on ISO 7206-4 or visit our Quality Standards page to see additional accredited test standards performed at our certified testing laboratory.