Biomechanical analysis of 3D printed porous extremely-low modulus Ti-24Nb-4Zr-8Sn lumbar interbody fusion cage-A finite element study

This study aimed to design and assess the biomechanical properties of a 3D-printed porous titanium alloy lumbar fusion cage, comparing it to traditional PEEK cages in lumbar PLIF surgery using finite element modelling. Employing Ti-24Nb-4Zr-8Sn (Ti2448) and Ti-6Al-4 V (Ti64) materials via EBM-3D printing, the fabricated cage exhibited enhanced mechanical stability when paired with the same internal fixation system. Biomechanical analysis revealed superior performance of both Ti2448 and Ti64 porous models over PEEK, notably Ti2448. These porous titanium cages effectively mitigate maximum stress at the cage-endplate interface, ensuring uniform stress distribution and minimizing subsidence risk. Additionally, their porous structure fosters osteogenesis, while the low modulus titanium alloy, resembling human cancellous bone, enhances interbody fusion and diminishes the probability of cage subsidence.