Bioengineering Sciences Research Group, Faculty of Engineering and the Environment, University of Southampton, UK.
J Biomech. 2013 Jul 26;46(11):1900-6. doi: 10.1016/j.jbiomech.2013.04.021. Epub 2013 Jun 10.
The aim of this study was to investigate the performance of a cementless osseointegrated tibial tray (P.F.C. ® Sigma®, Depuy® Inc, USA) in a general population using finite element (FE) analysis. Computational testing of total knee replacements (TKRs) typically only use a model of a single patient and assume the results can be extrapolated to the general population. In this study, two statistical models (SMs) were used; one of the shape and elastic modulus of the tibia, and one of the tibiofemoral joint loads over a gait cycle, to generate a population of FE models. A method was developed to automatically size, position and implant the tibial tray in each tibia, and 328 models were successfully implanted and analysed. The peak strain in the bone of the resected surface was examined and the percentage surface area of bone above yield strain (PSAY) was used to determine the risk of failure of a model. Using an arbitrary threshold of 10% PSAY, the models were divided into two groups ('higher risk' and 'lower risk') in order to explore factors that may influence potential failure. In this study, 17% of models were in the 'higher risk' group and it was found that these models had a lower elastic modulus (mean 275.7MPa), a higher weight (mean 85.3kg), and larger peak loads, of which the axial force was the most significant. This study showed the mean peak strain of the resected surface and PSAY were not significantly different between implant sizes.
本研究旨在通过有限元（FE）分析，研究非骨水泥型骨整合胫骨托（P.F.C. ® Sigma ® ，Depuy ® Inc.，美国）在普通人群中的性能。全膝关节置换术（TKR）的计算测试通常仅使用单个患者的模型，并假设结果可以外推到普通人群。在这项研究中，使用了两种统计模型（SM）；一种是胫骨的形状和弹性模量，另一种是步态周期中胫股关节的负荷，以生成一组 FE 模型。开发了一种自动调整胫骨托大小、位置和植入的方法，并成功地植入和分析了 328 个模型。检查了切除表面骨的峰值应变，并使用屈服应变以上的骨表面积百分比（PSAY）来确定模型失效的风险。使用 10% PSAY 的任意阈值，将模型分为两组（“高风险”和“低风险”），以探索可能影响潜在失效的因素。在这项研究中，17%的模型属于“高风险”组，发现这些模型的弹性模量较低（平均 275.7MPa），体重较大（平均 85.3kg），峰值负荷较大，其中轴向力最为显著。本研究表明，切除表面的平均峰值应变和 PSAY 在不同植入物尺寸之间没有显著差异。
