摘要
目的 :分析镍钛聚髌器这一髌骨骨折内固定器的设计合理性及治疗粉碎性髌骨骨折 ,促进骨折愈合的生物力学基础。 方法 :利用 ANSYS软件对聚髌器进行分析 ,建模后进行网格划分 ,有限元单元采用 2 0节点、八面体的三维砖块单元 ,六个定义自由度 ,共划分了 10 483个单元 ,节点数为 1795 9。髌骨三维有限元模型划分为 8775个单元 ,节点数 15 847。根据聚髌器的五个聚合方向 ,对髌骨模型施加载荷。结果 :镍钛聚髌器内表面受拉力 ,外表面受压力 ,其最大值分别为 195 .8MPa和- 18MPa,远小于其极限应力 ,同时亦远小于其疲劳极限。聚髌器的记忆加压聚合力为 134N。整个髌骨表面受力比较均匀 ,约为 0 .8Mpa。髌骨各节点应力计算表明 ,所受应力主要为正应力。结论 :本器设计合理 ,重复使用性好。固定后允许患者早期活动 (术后 ) 。
Objective: To analyze the design of Nitinol Patellar Concentrator (NT-PC) and its biomechanic characteristics for treating comminuted patellar fractures.Methods:NT-PC and patellar was analyzed by ANSYS software,the finite element was three dimension brick unit with 20 nodes, 8 faces, and the degree of freedom was 6.In NT-PC,10 483 units were divided and the number of nodes was 17 959;In Patellar,8 775 units were divided and the number of nodes was 15 847.The patellar model was loaded according to the 5 converging directions of NT-PC.Results:NT-PC had tension force on its internal face and pressure force in its external face.The maximum value was 195.8 MPa and -18 MPa,which was far from its utmost stress and fatigue limit.The memory converging force of NT-PC was 134 N.The stress (0.8 MPa) was evenly distributed on the patellar surface.Stress calculation of every node indicated that positive stress was the main stress.Conclusion: The design of NT-PC is reasonable and has good reusing character.After fixation, exercise is allowed immediately after operation.The continual positive stress is good for the stability of fracture end and fracture healing.
出处
《第二军医大学学报》
CAS
CSCD
北大核心
2001年第9期816-818,T003,共4页
Academic Journal of Second Military Medical University
基金
This project is supported by Shanghai Innovation Foundation of Technological Middle & Small Enterprise( No.0 0 7C2 6 2 2 310 0 749)
关键词
镍钛聚髌器
三维有限元分析
髌骨骨折
骨折内固定术
nitinol patellar concentrator
three dimensional finite element analyses
patellar fracture
