ASTM F1829 Glenoid shear test

The ASTM F 1829 describes a test method to determine the static shear force that must be applied to loosen modularly constructed glenoid components (insert and backing) of shoulder prostheses. The test is suitable for components made of metal alloys, polymers or composites and is used for design validation or comparison with other endoprostheses. As far as possible, the test should be oriented towards the clinical use of the implant. In explanation, test specimens, which are representative for the final product are tested and sterilized according to the manufacturer’s specification, as far as this is necessary. For testing, the test specimens are fixed parallel to the implant axis in the test machine and a vertical load is applied from inferior to superior and the rate of loosening is documented. The test is terminated in case of the following:

    1. rough deformation of the insert occurs without loosening
    2. the load has reached its maximum and starts to decrease rapidly
    3. the insert is detached from the backing

A new insert is then clamped into the test machine holder and the test is repeated, but this time the load is applied from superior to superior and aborted as soon as one of the three cases mentioned above occurs. The backing is checked visually for any damage after each test. A total of at least 5 equivalent samples should be used and the test should be carried out in circumambient air at room temperature or under defined physiological conditions.