Danielli Francesca, Wang Qingbo, Berti Francesca, Nespoli Adelaide, Villa Tomaso, Petrini Lorenza, Gao Chao
Department of Civil and Environmental Engineering, Politecnico di Milano, Milano, Italy; LaBS (Laboratory of Biological Structure Mechanics), Department of Chemistry, Materials and Chemical Engineering "Giulio Natta", Politecnico di Milano, Milano, Italy.
Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, Trondheim, Norway.
J Mech Behav Biomed Mater. 2025 Aug;168:107022. doi: 10.1016/j.jmbbm.2025.107022. Epub 2025 Apr 17.
Additive manufacturing technologies are commonly adopted for the fabrication of trabecular-based orthopedic prostheses made of titanium alloys due to their ability in producing complex and intricate designs. In this scenario, the use of finite element models represents a powerful tool for designing such devices and assessing their biomechanical behavior. Nevertheless, the usefulness of a numerical approach depends on the reliability of the adopted models, a crucial aspect when dealing with trabecular structures present within orthopedic implants. Indeed, the description of their effective geometry and the characterization of the material mechanical properties represent a tough challenge that hinders the development of high-fidelity numerical models. Specifically, the small dimensions of the trabeculae approach the accuracy limit of additive manufacturing leading to relevant uncertainties in their production. The existing studies dealing with the finite element modeling of 3D-printed trabecular structures often neglect the geometrical and material peculiarities of thin struts, making questionable the reliability of the developed numerical models. Namely, they either make simplifications in describing the mechanical properties of the material or do not account for realistic geometries. To address this gap, the present work aims to propose a systematic approach that achieves the development of accurate finite element models of trabecular structures, by integrating experimental activities with numerical simulations. This approach is exemplified by using two distinct trabecular structures used in the design of a custom talus prosthesis.
由于增材制造技术能够制造复杂精细的设计，因此常用于制造基于小梁的钛合金骨科假体。在这种情况下，使用有限元模型是设计此类装置并评估其生物力学行为的有力工具。然而，数值方法的有效性取决于所采用模型的可靠性，这在处理骨科植入物中的小梁结构时是一个关键问题。实际上，描述其有效几何形状和表征材料力学性能是一项艰巨的挑战，阻碍了高保真数值模型的发展。具体而言，小梁的小尺寸接近增材制造的精度极限，导致其生产中存在相关不确定性。现有关于3D打印小梁结构有限元建模的研究往往忽略了细支柱的几何和材料特性，使得所开发数值模型的可靠性受到质疑。也就是说，它们要么在描述材料力学性能时进行简化，要么不考虑实际几何形状。为了弥补这一差距，本研究旨在提出一种系统方法，通过将实验活动与数值模拟相结合，开发精确的小梁结构有限元模型。以定制距骨假体设计中使用的两种不同小梁结构为例说明了这种方法。
