Biomechanical effect of PEEK rod vs. metallic rod in spinal fusion constructs

Abstract

In this study we conducted a finite element analysis to investigate changes in load-sharing characteristics and the screw-bone loading of a PEEK rod system compared to a traditional titanium rod system when used as posterior instrumentation in conjunction with an interbody fusion. A 400N follower load, 14o Flexion, 8o extension was applied to an L1-S1 FE-model with fusion at L4-L5. Under compression, the load sharing between the anterior column support and posterior instrumentation is 70%-30% for the titanium rod and 85%-15% for the PEEK rod. The screw-bone loading for the PEEK rod is reduced by 85% and 71% in flexion and extension respectively when compared to a titanium rod. © 2010 International Federation for Medical and Biological Engineering.