In vitro spinal arthrodesis implant mechanical testing protocols.

Mechanical testing protocols and test methods used to evaluate spinal implants have varied widely. Use of different test methods would not present a problem except that multicomponent mechanical systems, such as the spine and spinal implant constructs, yield different mechanical properties when subjected to different test methods. The goal of this article is to outline considerations specific to the mechanical assessment of spinal implants. With standard test methods and treatment of results, redundancy between testing programs will be reduced and comparison of results will be facilitated.