Three-Dimensional Finite Element Analysis of a Complete Segment in the Lumbar Region (L3-L4) Under the Influence of Cage with Titanium and Peek Materials

The vertebrae are irregular bones with very complex shapes, which the study of the stress and strain distribution in them help to identify and evaluate their behavior. • Several biomechanical studies have been performed to improve the use of peek (Poly Ether Ether Ketone) or titanium cage for posterior lumbar intervertebral fusion (PLIF). This study was conducted to evaluate the biomechanical effect of these implants with different levels of hardness. So that for peek implants, the viscoelastic properties and elastic specific titanium implants are posed. To analyze the mechanical behaviors of a complete segment of the spine, a cage is initially designed in the SALIDWORK software, including the well-known cages for spinal vertebrae fusion, as well as two L3 and L4 vertebrae are designed in Abacus software and it is assembled with cage, the disk between the L3 and L4 vertebrae. According to the results obtained, the stress and strain rate in the vertebrae and cage with the peek material (due to the viscoelastic properties discussed in it) is significantly reduced compared to the titanium material, which is in good agreement with previous studies.