ASTM F2077: Intervertebral Body Fusion Device Testing
Intervertebral body fusion devices (IBFDs) are typically strut based or hollow structures in a geometric shape with teeth on the caudal and cephalad surfaces. By providing structural support, IBFDs reinforce the spine’s anterior column. An intervertebral body fusion device is used in clinical settings as one of the treatments for degenerative disc disease. They are surgically implanted spinal spacers comprised of either single or multiple components. Materials used typically include titanium and approved polymers, such as PEEK.
ASTM F2077, issued by the American Society for Testing and Materials (ASTM) is used to evaluate the mechanical performance of an intervertebral body fusion device when implanted into the body. These in vitro tests allow for a standardized loading process to be applied and analyzed.
The intended use of intervertebral body fusion devices requires that they can withstand normal everyday static and dynamic forces until the body has time to heal. The series of tests and methodology issued by ASTM is an International standard that all devices generally adhere to, which the FDA is the final arbiter of.
ASTM F2077 incorporates both fatigue and static testing methods for testing and evaluating intervertebral body fusion devices. These methods determine a device’s mechanical properties, specific to the cervical, and lumbar regions of the spine. Depending on the device’s intended spine location, dynamic and static axial compression, shear compression, and/or torsion mode tests are performed.
For static testing, the disc is simulated with a gap between two steel blocks having been prepared to hold the device. Static testing methods include compression, shear, and torsion evaluation along with subsidence (ASTM F2267) as needed.
A compression test involves placing the IBFD between the two stainless steel blocks and clamping those into the test frame. A constantly increasing load is then applied to the device until ultimate failure.
The shear test is performed similar to the compression test, with the only change being a shift in the incline of the bottom block base. This allows for both shear and compressive loads to be applied to the device at the same time.
Axial torsion testing subjects the device to a constant axial load while being subjected to a torsional force, or moment. Like compression testing, there are both functional and mechanical failures to be understood.
Fatigue testing simulates physiological loading but uses polyacetal blocks instead. The device is cyclically loaded by the frame until failure or 5M cycles, whichever happens first. In F2077, failure can be functional or mechanical. Functional failure occurs when the device no longer holds load. Mechanical failure occurs when the device has cracks or other mechanical or structural issues, but still is able to hold load. Depending on the indication and regulatory path one or both of these may be in play as failure criteria.
These methods quantify the dynamic and static characteristics of an intervertebral body fusion device’s design. To evaluate or compare the mechanical performance of different models, the results of these tests can reveal strengths and weaknesses due to design elements. For regulatory approval, a specific device has to meet or exceed a predicate (FDA cleared) devices’ performance or meet the acceptance criteria in the FDA published device performance papers on IBFDs.
Working with Empirical Technologies Corp.
If you are looking for trustworthy and reliable testing of intervertebral body fusion devices, Empirical Technologies has over 20 years of experience working closely with businesses and individuals to prepare their product for FDA submission successfully. As an industry leader in mechanical testing, Empirical Technologies has the expertise to conduct meticulous ASTM F2077 procedures – including utilizing only the tests needed for your device.
Given the complexity and demanding nature of ASTM F2077, ensuring quality and accuracy is best done in the hands of industry experts. There are many environmental variables that must be tightly controlled during testing, and we have the technical skills to ensure each step is executed to precision.
We can help you get your design up to ASTM standards and bring you one step closer to introducing your new body fusion device to regulatory bodies.