基于复合人工股骨的有限元模型构建及有效性验证

Finite element modeling and validation of composite artificial femur

摘要:

目的： 建立复合人工股骨的有限元模型并对其进行有效性验证。方法： 采用SAWBONE第4代复合人工股骨模型及正常人股骨尸体标本CT断层扫描数据各1例对股骨进行三维重建，重建出包含皮质骨、松质骨和髓腔结构的复合人工骨实体模型及正常人股骨三维模型共2组，并模拟股骨站立位状态下受到的轴向压缩载荷，对2组模型设定相同的边界条件，对比2组模型的应力分布情况并与国外文献数据进行模型的有效性验证。结果： 复合人工股骨有限元模型应力分布情况与既往文献数据较为一致，而尸体标本股骨总体应力分布显著低于人工股骨模型。结论： 复合人工股骨在有限元分析结果方面与既往文献存在较好的一致性，可用于股骨生物力学研究及骨科植入物的生物力学评估，且在材料来源以及个体化解剖差异因素方面相比尸体标本具有明显的优势。

Abstract:

Objective: To establish and validate a finite element model of composite artificial femur. Methods: A composite artificial femur of fourth generation SAWBONE and a normal human femur of cadaveric specimen were selected to conduct three-dimensional reconstruction of femur via computed-tomography scan. Two groups of composite artificial bone entity models including cortical bone, cancellous bone, and medullary cavity and three-dimensional model of normal human femur were reconstructed. A load case of axial compression during mid-stance gait of lower extremities was simulated while an identical boundary condition was applied to both groups of models. The model validation of composite artificial femur was conducted according to the comparison of biomechanical response among the two groups and the results from previous literature. Results: Regarding to the peak stress distribution and the magnitude of displacement peak value, the finite element model of composite artificial femur presented relatively in good accordance with results from previous literature. Nevertheless, the biomechanical response of cadaveric femur presented significantly lower stress distribution comparing to that of the composite femur model. Conclusion: The results of finite element analysis of composite artificial femur are in good agreement with previous literatures, which can be used for biomechanical research of femur and biomechanical evaluation of orthopedic implants, and has obvious advantages over cadaveric specimens in terms of material sources and individual anatomical differences.