2022 Fiscal Year Final Research Report

Guiding principles for design of ultra-anisotropic stiffness function of metallic implants for bone fixation

Research Project

PDF

Project/Area Number	20H02036
Research Category	Grant-in-Aid for Scientific Research (B)
Allocation Type	Single-year Grants
Section	一般
Review Section	Basic Section 18010:Mechanics of materials and materials-related
Research Institution	Kindai University
Principal Investigator	Nakai Masaaki 近畿大学, 理工学部, 教授 (20431603)
Co-Investigator(Kenkyū-buntansha)	山本衛近畿大学, 生物理工学部, 教授 (00309270) 京極秀樹近畿大学, 次世代基盤技術研究所, 教授 (10258056) 坂田誠一郎近畿大学, 理工学部, 教授 (80325042) 植木洸輔近畿大学, 理工学部, 講師 (10845928)
Project Period (FY)	2020-04-01 – 2023-03-31
Keywords	生体材料 / ステンレス鋼 / 金属積層造形 / 結晶方位配向 / ヤング率 / 異方性 / 骨固定 / インプラント
Outline of Final Research Achievements	Low stiffness in the axial direction is required to suppress stress shielding, whereas high stiffness in the shear direction is required to promote bone healing in metallic implants. Therefore, using an additive manufacturing technique, metallic plates having a low Young's modulus in the longitudinal direction and high Young's modulus in the lateral direction were tried to be fabricated by controlling crystallographic orientation. 316L stainless steel was used as a material, and two types of crystallographic orientations were set to be <100>/<110> and <110>/<111> along two in-plane orthogonal directions. As the results, the fabricated plates with the Young's modulus higher in the lateral direction than that in the longitudinal direction could be obtained successfully. However, the Young's modulus of fabricated plates was different from that of single crystal. It is considered that this difference can be decreased by optimizing the fabrication process.
Free Research Field	生体材料学、金属材料学
Academic Significance and Societal Importance of the Research Achievements	既に超高齢社会となっている我が国では、骨疾患の症例数も増加しており、金属インプラントの使用機会が増加している。それにもかかわらず、我が国の金属インプラントの市場は、外国製品に頼っており、国産製品が占める割合は極めて小さい。しかし、本研究のように新たな機能を持たせて付加価値の高い金属インプラントが開発されれば、実際にそれを利用する医師や患者にとって有益であるとともに、外国製品との差別化より競争力のある国内産業の創出にも貢献すると考えられる。