Fused filament fabrication-3D printing of poly-ether-ether-ketone (PEEK) spinal fusion cages

Fused Filament Fabrication (FFF)-3D printing can be a powerful manufacturing tool for developing design-specific and patient-specific medical implants. In this study, we used the FFF to 3D print a high-performance polymer known as Poly-ether-ether-ketone (PEEK) for a load-bearing application. Specifically, we 3D printed resilient PEEK interbody fusion cages, a critical implant in spinal fusion surgeries. However, the FFF of PEEK structures is challenging because PEEK requires high melting temperatures and is prone to warping and incomplete crystallization, negatively affecting the fusion cages' strength. Hence, for the first time, in this study, we vary critical FFF processing parameters such as nozzle, chamber, and bedplate temperature and analyze their influence on the cages' mechanical and thermal properties. Our results indicate that increasing thermal parameters helps better layer fusion and adhesion and augments the cages' crystallinity, thus enhancing their mechanical properties.