ASTM F1717: Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy Model
The ASTM F1717 standard is the standard testing methodology for spinal implant constructs in a vertebrectomy model. Spinal implants commonly tested under F1717 are screws/rod or hook constructs and anterior cervical or lumbar plates.
Currently, all constructs are tested under F1717 before FDA or EU submission to determine their fatigue life. This is the maximum load that they can take for 5M cycles without a failure. Failure can be fracture of the screw, rod or plate, or it can be the construct failing to maintain load by rotation of the screws or bending of the rod/plate. We generally run 6 specimens to determine the FN (load v cycle) curve. Most commonly we confirm the runout load with 2 specimens to give a higher level of confidence to the reported outcome.
Testing is specific to the implant, as there are many combinations of spinal implant components. Specific tests are designed depending on the intended spinal location and the surgical technique. Components of spinal implant constructs typically include hooks, screws, rods, plates, rod extenders, and interconnections. As there are not specific subcomponent tests, it is often a good strategy to test multiple components in a worst-case construct so that all the permutations can be approved in a single submission.
The ultimate goal of the testing is often to meet or exceed predicate data and submit to FDA or CE. For these types of constructs, customers general choose an acceptance criterion, or have Empirical draft a protocol with the acceptance criteria for them. All the testing is performed with an eye on the acceptance criteria to make sure that the system is performing as needed to be able to move forward to regulatory for approval.
ASTM F1717: Spinal Constructs Device Testing
Both static and fatigue testing methods are used to assess spinal implant construct. ASTM F1717 procedural guidelines are often used to establish a basis of mechanical comparison of spinal implant constructs, but they do not define performance levels.
ASTM F1717 has three static and one fatigue tests. These tests try to find the threshold that causes mechanical failure in the spinal device construct. Even without bone support, the implant should be able to bear the load and load transfer between the vertebral bodies. This setup is a worst case where an entire motion segment plus a disc has been removed. While not directly clinically relevant, it represents a worst case that all parties could agree on to compare against. As all implants go thru the same process, it provides a parametric comparison of performance between systems.
The static tests include torsion, tension bending, and compression bending. Static compression bending tests involve UHMWPE blocks to simulate vertebrae for the spinal implant assembly. A compression bending test is the most common fatigue test. The mechanical tests do not mimic complex spine loads and motion segments; instead, they use simplified loading schemes to facilitate comparison by regulators.
Testing is tailored and performed specifically to the location of the spine it supports. The various components and materials must uniquely be tested as well, meaning that ASTM F1717 require a precise approach.
If you are seeking FDA approval for a spinal implant construct, ASTM F1717 is a critical part of the larger regulatory submission.
Working with Empirical Technologies Corp.
At Empirical Technologies, we have 20 years of trusted experience working with individuals and businesses to prepare their products for FDA submission successfully. We offer ASTM F1717 testing, uniquely optimized to the components and attributes of your model. Our team of exceptional and talented professionals has the focus and skill to maintain ideal environmental climates and capture a comprehensive mechanical overview.
As an industry leader in mechanical testing, Empirical Technologies has the resources to prepare your spinal implant construct for U.S. and global markets. We perform all aspects of ASTM F1717, thereby assessing the spinal implant construct under different environmental simulations that mimic the environment it is intended to be in.
Contact us today to request a quote for ASTM F1717 testing for your spinal implant constructs.