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.
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.
Please refer to the ASTM website for the most up to date information on ASTM F1717 or visit our Quality Standards page to see additional accredited test standards performed at our certified testing laboratory.