The discrete nature of trabecular bone microarchitecture affects implant stability.
The discrete nature of trabecular bone microarchitecture affects implant stability.
复制标题
小梁骨微结构的离散性质影响种植体的稳定性。
DOI：
10.1016/j.jbiomech.2011.12.024
复制
发表时间：
2012
影响因子：
2.4
通讯作者：
G. H. van Lenthe
中科院分区：
文献类型：
--
作者：
A. Wirth;R. Müller;G. H. van Lenthe
小型骨内植入物，如螺丝，是现代骨科和牙科的重要组成部分。因此，它们必须可靠地满足各种要求，这使得此类植入物的开发具有挑战性。有限元分析是一种广泛使用的计算工具，用于分析和优化种植体在骨中的稳定性。出于这些目的，通常将骨骼建模为连续介质材料。然而，骨衰竭和骨适应过程发生在单个骨小梁的离散水平；因此，在这个水平上的应力和应变的评估是相关的。因此，本研究的目的是调查连续体假设如何影响种植体周围应变分布和种植体与骨之间的载荷转移。我们进行了一项计算研究，将松质骨螺钉插入连续和离散的松质骨模型中；模拟了轴向载荷。我们发现在离散型和连续型骨模型中，植入物的硬度有很大的差异。它们取决于骨密度和应用的边界条件。此外，在连续模型和离散模型中，从螺钉到周围骨的载荷转移有很大的不同，特别是对于低密度骨。根据我们的研究结果，我们得出结论，当需要精确量化种植体周应力和应变时，连续体骨模型在种植体周围骨小梁中的力学载荷有限元分析中的应用有限。因此，对于骨小梁植入物的评估和改进，应该使用能够准确反映骨小梁微结构的有限元模型。
Small endosseous implants, such as screws, are important components of modern orthopedics and dentistry. Hence they have to reliably fulfill a variety of requirements, which makes the development of such implants challenging. Finite element analysis is a widely used computational tool used to analyze and optimize implant stability in bone. For these purposes, bone is generally modeled as a continuum material. However, bone failure and bone adaptation processes are occurring at the discrete level of individual trabeculae; hence the assessment of stresses and strains at this level is relevant. Therefore, the aim of the present study was to investigate how peri-implant strain distribution and load transfer between implant and bone are affected by the continuum assumption. We performed a computational study in which cancellous screws were inserted in continuum and discrete models of trabecular bone; axial loading was simulated. We found strong differences in bone-implant stiffness between the discrete and continuum bone model. They depended on bone density and applied boundary conditions. Furthermore, load transfer from the screw to the surrounding bone differed strongly between the continuum and discrete models, especially for low-density bone. Based on our findings we conclude that continuum bone models are of limited use for finite element analysis of peri-implant mechanical loading in trabecular bone when a precise quantification of peri-implant stresses and strains is required. Therefore, for the assessment and improvement of trabecular bone implants, finite element models which accurately represent trabecular microarchitecture should be used.