Computational analysis of L4–L5 interspinous process devices and interbody fusion spacers using ceramic and polymeric materials via finite element modeling and artificial intelligence

Comprehensive Summary

This study investigates the biomechanical performance of several materials in anterior lumbar interbody fusion (ALIF) spacers and interspinous process (ISP) devices at the L4–L5 spinal level. Finite element analysis (FEA) and artificial intelligence (AI) were combined to formulate a two-phase computational framework for measuring implant stress, stress and strain in adjacent vertebrae, and segmental range of motion, while also potentially performing patient-specific material selections. For ISP devices, stiffer materials such as ceramics and 60% carbon fiber-reinforced polyether ether ketone (CFR-PEEK 60%) significantly reduced stress and strain transmitted to adjacent vertebrae, while in ALIF spacers, more compliant polymers such as polyether ether ketone (PEEK) and polyether ketone ketone (PEKK) showed improved load sharing in osteoporotic spines. The study, however, is limited by assumptions of linear elastic, isotropic material behavior and the lack of explicit modeling of osteoporotic bone microstructural changes.

Outcomes and Implications

Lumbar spinal stenosis (LSS) and degenerative disc disease (DDD) are common spinal conditions often requiring surgical intervention and the use of specialized implants and devices. These components are traditionally made from titanium alloys, which have many drawbacks, such as MRI imaging artifacts, potential electronic interference, inflammatory or hypersensitivity reactions, and high manufacturing costs. With the computational framework described in this study, these drawbacks could be mitigated with the identification of alternative materials, and patients could be assigned based on their specific bone attributes to improve clinical outcomes. Although the author does not specifically comment on clinical implementation, they suggest that future validation, such as testing with physical cadavers, should be conducted before these results are applied to real-world applications.