摘要
目的:在缺少层厚较薄的CT和MRI数据的情况下建立膝关节骨性关节炎(KOA)轻症患者膝关节三维有限元模型,并研究胫骨平台内外侧的应力分布。方法:以一名患有轻度KOA的女性患者为研究对象,自盆骨至腓骨胫骨远端进行连续断层扫描。将得到的DICOM格式文件导入至Mimics软件中并通过阈值分割提取膝关节中的骨性结构,将提取出的骨骼进行蒙版编辑、空腔填充、区域增长等操作后导入3-matic中做光顺、包覆处理。在Geomagic Wrap将处理后的骨性结构使用网格医生检查,修复表面缺陷并拟合曲面。以轮廓延展的思路建立相关的软骨、半月板和韧带,并在SolidWorks中以原点重合的方式与骨性结构进行装配。接下来在ANSYS软件中定义材料、设置接触、划分网格、设置约束和载荷,分析在双腿站立下胫骨平台上的应力分布情况。结果:成功建立了包括骨性结构、软骨、韧带的完整膝关节模型。在双腿站立状态下,接触应力峰值约为1.21 MPa,位于胫骨平台内侧中部,胫骨平台外侧的最大应力为0.72 MPa,内外侧间室分别承担总载荷的62.7%和37.3%。结论:通过CT提取加软件绘制的方式建立了全膝关节模型,有限元分析结果符合临床预期,通过此方法建立的模型可靠,能进行后续的研究。
Objective To establish a three-dimensional finite element model of knee joint in patients with mild knee osteoarthritis in the absence of CT and MRI with thin layer thickness,and to analyze the stress distributions of the tibial plateau.Methods A female patient with mild knee osteoarthritis was selected as the study object,and received serial CT scan from pelvis to distal tibia of fibula.The obtained files in DICOM format were imported into Mimics software for extracting the bony structures of knee joint through threshold segmentation,and then optimizing the extracted structures with Edit Masks,Cavity Fill and Region Grow.The generated model of bony structures was imported into 3-matic for smoothing and wrapping,and Geomagic Wrap was used for bony structure processing with mesh doctor inspection,surface defect repair and surface fitting.The cartilages,meniscus and ligaments were established by contour extension,and assembled with bony structures in SolidWorks in the way of origin coincidence.After defining material properties and contact relationships,meshing,and setting constraints and loads in ANSYS software,the stress distributions of the tibial plateau when standing with both legs were analyzed.Results A complete knee joint model including bony structure,cartilage and ligament was successfully established.When standing with two legs,the peak value of contact stress was about 1.21 MPa,and the maximum stress was 0.72 MPa at the medial middle of tibial plateau and lateral tibial plateau.The 62.7%and 37.3%of the total load were borne by the inner and outer compartments.Conclusion The model of the total knee joint is established with CT extraction and software rendering,and the finite element analysis results meet clinical expectations,indicating that the model established by the proposed method is reliable and can be used for follow-up research.
作者
周陶勇
杨永盛
鲁宁
唐浩
杨延东
韩谢川
ZHOU Taoyong;YANG Yongsheng;LU Ning;TANG Hao;YANG Yandong;HAN Xiechuan(Faculty of Mechanical and Electrical Engineering,Kunming University of Science and Technology,Kunming 650500,China;Department of Orthopedics,the Second Affiliated Hospital of Kunming Medical University,Kunming 650500,China)
出处
《中国医学物理学杂志》
CSCD
2024年第3期382-388,共7页
Chinese Journal of Medical Physics
基金
国家自然科学基金(52165067)。
