ASTM F2789 covers the standard test method for mechanical testing of replacement or augmentation devices for the nucleus pulposus of the intervertebral disc. ASTM F2789 covers static and dynamic testing procedures for axial compression, axial torsion, shear, and bending and functional testing for functional range of motion, lifiting force, viscoelastic properties, and subsidence. Nucleus devices are designed for use with intact or partially intact annulus fibrosus, so all tests allow for the use of a surrogate annulus, to better simulate the in vivo use of the nucleus device.
Testing Procedure
Dynamic and fatigue testing is conducted until the nucleus device fails or 10 million cycles is reached. This fatigue and wear life of 10 million cycles is a typical benchmark for implanted medical devices. ASTM F2789 recommends testing the nucleus device in a physiologic solution maintained at 37 degrees Celsius. Viscoelastic testing of the nucleus device is accomplished by performing a creep/creep-recovery or stress relaxation test. These tests require both force and strain control capabilities.
Equipment Required
By means of our testing expertise and modular product design, we will help find the solution that is right for you. Give our test engineers a call today for help configuring the best test machine and accessories according to ASTM F2789.
