Assessing the use of finite element analysis for mechanical performance evaluation of intervertebral body fusion devices

Andrew P Baumann; Thomas Graf; Jonathan H Peck; Anton E Dmitriev; Dezba Coughlan; Jeffrey C Lotz

doi:10.1002/jsp2.1137

Assessing the use of finite element analysis for mechanical performance evaluation of intervertebral body fusion devices

JOR Spine. 2021 Jan 13;4(1):e1137. doi: 10.1002/jsp2.1137. eCollection 2021 Mar.

Authors

Andrew P Baumann¹, Thomas Graf¹, Jonathan H Peck², Anton E Dmitriev¹, Dezba Coughlan³, Jeffrey C Lotz³

Affiliations

¹ Office of Science and Engineering Laboratories, Center for Devices and Radiological Health U.S. Food and Drug Administration Silver Spring Maryland USA.
² Office of Product Evaluation and Quality, Center for Devices and Radiological Health U.S. Food and Drug Administration Silver Spring Maryland USA.
³ Department of Orthopaedic Surgery University of California, San Francisco San Francisco California USA.

Abstract

Background: Intervertebral body fusion devices (IBFDs) are a widely used type of spinal implant placed between two vertebral bodies to stabilize the spine for fusion in the treatment of spinal pathologies. Assessing mechanical performance of these devices is critical during the design, verification, and regulatory evaluation phases of development. While traditionally evaluated with physical bench testing, empirical assessments are at times supplemented with computational models and simulations such as finite element analysis (FEA). However, unlike many mechanical bench tests, FEA lacks standardized practices and consistency of implementation.

Objectives: The objectives of this study were twofold. First, to identify IBFD 510(k) submissions containing FEA and conduct a comprehensive review of the elements provided in the FEA reports. Second, to engage with spinal device manufacturers through an anonymous survey and assess their practices for implementing FEA.

Methods: First, a retrospective analysis of 510(k) submissions for IBFDs cleared by the FDA between 2013 and 2017 was performed. The contents of FEA test reports were quantified according to FDA guidance. Second, a survey inquiring about the use of FEA was distributed to industry and academic stakeholders. The survey asked up to 20 questions relating to modeler experience and modeling practices.

Results: Significant gaps were present in model test reports that deemed the data unreliable and, therefore, unusable for regulatory decision-making in a high percentage of submissions. Nonetheless, the industry survey revealed most stakeholders employ FEA during device evaluation and are interested in more prescriptive guidelines for executing IBFD models.

Conclusions: This study showed that while inconsistencies and gaps in FEA execution do exist within the spinal device community, the stakeholders are eager to work together in developing standardized approaches for executing computational models to support mechanical performance assessment of spinal devices in regulatory submissions.

Keywords: finite element analysis; intervertebral body fusion device; modeling; simulation.

Published [2021]. This article is a U.S. Government work and is in the public domain in the USA. JOR Spine published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.