Engineering intervertebral disc replacements using 3D-printed open Gyroid architectures

Degenerative disc disease is a leading cause of chronic back pain, and current surgical treatments such as fusion and disc arthroplasty remain limited by implant wear, stress shielding, and mechanical mismatch with the native intervertebral disc (IVD). This study investigates three-dimensional (3D) printed thermoplastic polyurethane (TPU) Gyroid structures as biomimetic disc replacements. Using filaments of varying stiffness, 3D-printed constructs demonstrated high geometric fidelity and mechanical performance within physiological load and deformation ranges. Dynamic compression testing revealed damping coefficients of approximately 16%, closely matching native IVD behavior. Stiffness scaled predictably with structural density, allowing mechanical tuning toward physiological properties. These findings highlight the potential of Gyroid-structured TPU implants to replicate the natural damping and load distribution of human discs, offering a pathway toward customizable, patient-specific disc replacements. Future work will focus on medically approved TPU, biological responses, and multiaxial loading.