Effects of Material Properties in Spinal Fusion Cage for Lumbar Vertebrae

Vertebral endplate subsidence failure will increase the possibility of mechanical instability in the lumbar spinal fusion. The spinal implants of cages are many type of design that can be use in spinal fusion and the type of material also been considerate. Posterior lumbar interbody fusion (PLIF) cage is believed to maintain the stability and to promote fusion between vertebrae. Different type biomaterial of cage was made by metal, ceramic and polymer, also composite. The Posterior Instrument (PI) such pedicle screw and rod was made by Titanium Alloy. The aim of this study was to examine the effects of different materials of cage in lumbar fusion. 3D vertebrae model (L3-L4) with interbody fusion using different material properties such as PEEK, PLA, Cobalt Chromium, Titanium Alloy and Stainless Steel. A fusion model with pedicle screw systems L3-L4 levels were reconstructed based on the respective surgical protocols. The stress distribution and total deformation of the cage were measured under different compressive loading conditions and motion. Results show that the titanium alloy is the best material for metal categories while PLA (Poly lactic acid) for composite category.