髌骨骨折AO张力带内固定有限元模型的建立和分析

背景：目前有关髌骨骨折内固定的生物力学研究大多集中在尸体标本上，应用现代有限元法进行分析的报道较少。 目的：建立髌骨骨折AO张力带内固定的三维有限元模型，并对所建模型进行有限元力学分析。 方法：选择1名成年女性志愿者，行下肢薄层CT扫描，将图像数据导入Mimics 10.01 软件通过Region growing提取右侧髌骨polylines，导入Geomagic studio 10.0建立髌骨几何模型。将髌骨几何模型导入PRO/E 2.0软件中，利用软件中的分割功能模拟髌骨骨折，利用软件中的扫描功能，生成两根折弯的克氏针和环形钢丝，建立三维髌骨骨折AO张力带内固定模型，导入ANSYS中建立三维有限元模型，模拟屈膝90°髌股关节作用力600 N进行有限元分析，分析其位移及变形特点。 结果与结论：AO张力带有多向加压作用，及明显对抗股四头肌向上拉应力的作用。提示有限元分析结果与生物力学结果相符，建立的髌骨骨折AO张力带内固定有限元模型有效，有助于更全面了解张力带内固定髌骨骨折的生物力学原理，为临床治疗提供借鉴。

Construction and analysis of a finite-element model of patella fracture fixed with AO tensile force girdle

BACKGROUND:Currently, most of biomechanical research about internal fixation of patellar fracture has been carried out by corpse. Few researchers carried out it using modern finite element method. OBJECTIVE:To establish the finite element model of patella fracture fixed with AO tensile force girdle and to perfore finite element mechano-analysis. METHODS:An adult female volunteer was selected, underwent a lamellar computed tomography (CT) scan on the lower extremity, extract right patella’s polylines by Mimics10.01 software and construct geometrical models. Then the geometrical model was imported into PRO/E 2.0 software, to simulate bone fracture by intersected function of PRO/E 2.0 software and generate two bent Kirschner wires and annular steel-wire, rebuild 3D model of patella fracture fixed with AO tensile force girdle. After that, the model was imported into the ANSYS software to constructe 3D finite-element models that analyzing displacement and deformation features simulating patellofemoral joint under 600 N loading at 90° knee bending.   RESULTS AND CONCLUSION:The AO tensile force girdle could force patella fracture in many ways, and opposed to tensile force of musculus quadriceps fexoris. The finite element analytic result coincides with biomechanical result. The 3D finite-element model of patella fracture fixed with AO tensile force girdle was scientific, which is beneficial to better understanding of the biomechanical principle about patella fracture fixed with AO tensile force girdle and provides clinical instruction.