Department of Mechanical Engineering, Faculty of Engineering, University of Alberta, Edmonton, AB, Canada.
Department of Biomedical Engineering, Faculty of Engineering & Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
Ann Biomed Eng. 2024 Nov;52(11):2987-3008. doi: 10.1007/s10439-024-03561-6. Epub 2024 Jul 8.
Evaluating the bone-implant interface (BII) properties of osseointegrated transfemoral (TFA) implants is important for early failure detection and prescribing loads during rehabilitation. The objective of this work is to derive and validate a 1D finite element (FE) model of the Osseointegrated Prosthetic Limb (OPL) TFA system that can: (1) model its dynamic behaviour and (2) extract the BII properties. The model was validated by: (1) comparing the 1D FE formulation to the analytical and 3D FE solutions for a simplified cylinder, (2) comparing the vibration modes of the actual TFA geometry using 1D and 3D FE models, and (3) evaluating the BII properties for three extreme conditions (LOW, INTERMEDIATE, and HIGH) generated using 3D FE and experimental (where the implant was embedded, using different adhesives, in synthetic femurs) signals for additional validation. The modes predicted by the 1D FE model converged to the analytical and the 3D FE solutions for the cylinder. The 1D model also matched the 3D FE solution with a maximum frequency difference of 2.02% for the TFA geometry. Finally, the 1D model extracted the BII stiffness and the system's damping properties for the three conditions generated using the 3D FE simulations and the experimental INTERMEDIATE and HIGH signals. The agreement between the 1D FE and the 3D FE solutions for the TFA geometry indicates that the 1D model captures the system's dynamic behaviour. Distinguishing between the different BII conditions demonstrates the 1D model's potential use for the non-invasive clinical evaluation of the TFA BII properties.
评估骨整合股骨（TFA）植入物的骨-植入物界面（BII）特性对于早期故障检测和康复期间的负载规定很重要。本工作的目的是推导和验证可：（1）模拟其动态行为，（2）提取 BII 特性的 Osseointegrated Prosthetic Limb（OPL）TFA 系统的一维有限元（FE）模型。通过以下方法验证模型：（1）将一维 FE 公式与简化圆柱的解析和三维 FE 解决方案进行比较，（2）使用一维和三维 FE 模型比较实际 TFA 几何结构的振动模式，以及（3）使用三维 FE 和实验（其中植入物使用不同的粘合剂嵌入在合成股骨中）信号生成三种极端情况（LOW、INTERMEDIATE 和 HIGH）评估 BII 特性，进行额外验证。一维 FE 模型预测的模式收敛到圆柱的解析和三维 FE 解决方案。一维模型还与三维 FE 解决方案匹配，TFA 几何结构的最大频率差异为 2.02%。最后，一维模型从三维 FE 模拟生成的三种条件（LOW、INTERMEDIATE 和 HIGH）以及实验的 INTERMEDIATE 和 HIGH 信号中提取了 BII 刚度和系统阻尼特性。TFA 几何结构的一维 FE 和三维 FE 解决方案之间的一致性表明，一维模型捕获了系统的动态行为。区分不同的 BII 条件表明，一维模型可用于非侵入性临床评估 TFA BII 特性。
