ASTM F2706 – Standard Test Methods for Occipital-Cervical and Occipital-Cervical-Thoracic Spinal Implant Constructs in a Vertebrectomy Model
These test methods cover the materials and methods for the static and fatigue testing of occipital-cervical and occipitalcervical-thoracic spinal implant assemblies in a vertebrectomy model. The test materials for most combinations of occipitalcervical and occipital-cervical-thoracic spinal implant components can be specific depending on the intended location and intended method of attachment. These test methods are intended to provide a basis for the mechanical comparison among past, present, and future occipital-cervical and occipital-cervical-thoracic spinal implant assemblies. They allow comparison of occipital-cervical and occipital-cervical-thoracic spinal implant constructs with different methods of application to the spine. These test methods are not intended to define levels of performance, since sufficient knowledge is not available to predict the consequences of the use of a particular device.
There are three static test method and two fatigue test methods. The static test methods are: Compression Bending, Tension Bending, and Torsional Test. The customer will request when a Tension Bending test shall be performed.
The Bending fatigue test applies a sinusoidal load to the spinal construct. The loading should be maintained via a constant sinusoidal load amplitude control. A constant load ratio (R) for all tests should be established and should be equal to or greater than 10. The fatigue test is typically conducted at 5 Hertz (maximum frequency allowed) for 5 million cycles or until failure, whichever occurs first.
The Torsion fatigue test applies a fully-reversed sinusoidal load to the spinal construct. The loading should be maintained by controlling torque amplitude. The fatigue test is typically conducted at 5 Hertz (maximum frequency allowed) for 5 million cycles or until failure, whichever occurs first.
There are a total of 6 samples tested for each test method. Example of test results are shown below.