Spinal Implant Testing

The linked FDA Guidance Document published in 2007 applies to intervertebral Body Fusion Devices which are implanted single or multiple-component spinal devices made from a variety of materials, including titanium and polymers. The device is inserted into the intervertebral body space of the cervical or lumbosacral spine, and intended for intervertebral body fusion. Mechanical Testing Overview The FDA Guidelines recommend that test constructs comprised of components are of the worst case (e.g., most likely to fail) final design version. The components tested should comprise the worst case constructs in terms of design, materials, and manufacturing-related processing. For the intervertebral body fusion device, the FDA recommends that you provide complete test reports for: static and dynamic torsion testing of cervical intervertebral body fusion devices, static and dynamic axial compression and compression shear testing of lumbar and cervical intervertebral body fusion devices, and subsidence testing of lumbar and cervical intervertebral body fusion devices.

Depending on the specific design (e.g., anterior cord design), material (e.g., polymer, composite), and/or method of attachment, you may be required to perform additional testing (e.g., dynamic torsion testing, expulsion testing, creep testing) for a given intervertebral body fusion device. Static and Dynamic Tests FDA recommends that static and dynamic construct testing should involve a minimum of six samples of the worst case construct. Static and dynamic construct testing is most commonly performed in accordance with ASTM F2077-03 Test Methods For Intervertebral Body Fusion Devices. ASTM F2077-03 provides a standard comparison to predicate device testing and allows a declaration of conformity for static and dynamic testing. Additional testing to ASTM F2077-03 may be required if your intervertebral body fusion device is manufactured out of a polymer or another material. Dynamic testing should involve a minimum of six samples of the worst case construct to generate a semi-log plot of load versus cycles to failure. FDA defines the end of the test as functional failure of the construct or attainment of 5,000,000 cycles without functional failure. Compare the results to those obtained from an appropriate predicate intervertebral body fusion device. Test a minimum of two samples at the lowest load level in order to establish a resulting endurance load limit.

Subsidence Tests The FDA recommends you follow ASTM F2267 Standard Test Method for Measuring Load Induced Subsidence of an Intervertebral Body Fusion Device Under Static Axial Compression, or equivalent method. The FDA recommends you follow ASTM F2267 to provide a standard comparison to predicate device testing and to allow a declaration of conformity to that standard. ASTM F2267 is based on metallic implants and may not be applicable if your device is made out of other materials. Therefore, additional testing and/or modifications to ASTM F2267 may be required if your intervertebral body fusion device is manufactured out of a polymer or other materials. Test Report FDA Guidelines mention that you should provide a complete test report that includes: identification of the worst case intervertebral body fusion device tested the rationale for considering the intervertebral body fusion device worst case the rationale for the loading modes chosen (e.g., axial, bending, torsion) the results a discussion of the results in terms of the expected in vivo and clinical performance of the assembly. If there are differences between the device you intend to market and the device actually tested (e.g., tests were performed on a prototype), then the FDA recommends that you explain why the results are relevant to the device you intend to market. Note this brief article references FDA Guidelines but does not include extensive and critical information required to meet FDA regulatory requirements. Contact the FDA for their full support. The original source of the information presented above is the FDA and TestResources intent is to facilitate and encourage you to contact them for further information regarding their requirements and expectations regarding all regulatory matters.

Applicable Testing Standards

Recommended Test Machines