Block-Fixation Finite Element Lumbar Spine Model to Examine Load-Sharing, Bone-Screw Interaction, and Stress in Carbon Fiber Reinforced PEEK Construct

Carbon-fiber-reinforced (CFR) polyetheretherketone (PEEK) combines the high strength of metals with the extensive biocompatibility and imaging compatibility of polymers. CFR PEEK composite is similar to the stiffness of cortical bone (approximately 15–20 GPa) and shows comparable performance to metallic materials such as titanium alloy, cobalt chrome alloy, and stainless steel in terms of strength. CFR-PEEK becomes an attractive alternative to the metallic materials traditionally used in spinal implants (e.g. pedicle screw rod fixation). Finite element (FE) models have been developed to study the biomechanical behaviors of spinal structures with pedicle screw rod fixation ([1–5]). However, it is limited to implement these models to study the bone screw interaction, and local bone strain at the bone screw interface due to the intrinsic low mesh density of the intact model. The aim of this study is to develop a refined block fixation FE model to investigate the load sharing, bone screw interaction, and strain/stress in CFR PEEK construct.