3D printed titanium TPMS for personalised tibial bone implant

Abstract

Abstract: Porous titanium scaffolds offer hope for reducing stress shielding and encouraging new bone growth, moving the field closer to personalised load bearing implants. This study explores four triply periodic minimal surface (TPMS) tibial scaffolds informed by Gyroid (GSC), Lidinoid (LSC), Diamond (DSC), and Schwartz Primitive (SSC) unit cells. These scaffolds were made using Laser Powder Bed Fusion (L-PBF) 3D printing, with a targeted porosity of 60 % to closely match the mechanical behaviour of natural tibial bone. Mechanical testing of these scaffolds revealed an elastic modulus of 10.42 to 13.62 GPa and compressive strengths ranging from 209 to 393 MPa, meeting the requirements for load-bearing tibial implants. Multi-criteria decision-making (MCDM) methods, AHP and TOPSIS, were applied to evaluate the designs, considering four favourable factors of relative importance in the order porosity>yield strength>elastic modulus>ultimate strength. This analysis identified SSC scaffold featuring Schwartz Primitive architecture as the most promising candidate for load-bearing applications. The biological compatibility of these scaffolds was also found to be equally compelling. In vitro testing with U-2OS osteosarcoma cells confirmed high cell viability, underscoring the cytocompatibility of these TPMS designs and reinforcing their potential for biomedical applications. Together, these findings offer a path toward the use of titanium scaffolds in orthopaedics, setting the stage for further in vivo studies and a potential breakthrough in functional bone implant design.