摘要
目的:探讨髋臼三维记忆内固定系统治疗髋臼后壁骨折及其产生的动态记忆应力促进骨愈合的生物力学基础。方法:实验于2006-01在长海医院进行。利用计算机仿真三维有限元技术,对髋臼记忆内固定系统固定髋臼后壁骨折的生物力学行为进行模拟,BaⅡ型三维有限元模型共划分7946个单元,2520个结点;BbI型三维有限元结构共划分1787个单元,623个结点,单元采用TET4单元;髋臼有限元模型共划分5783个单元,节点数为9863,单元采用10节点四面体三维单元。结果:①变形最大在加压部,BaⅡ型所受最大压应力和张应力分别为228MPa和-24.5MPa,其维持纵向的动态记忆持骨力196N;BbI型所受压应力和张应力分别为108MPa和-4.5kPa,其维持轴向的动态记忆加压力为125.05N,二者皆远小于其极限应力及疲劳极限。②被固定髋臼后壁骨块应力分布均匀,各节点所受应力主要为接近生理载荷的正应力,无论在后壁骨折的上、下及内侧骨折面,骨折断层的应力分布表现为记忆导向孔附近应力较大,为垂直骨折面的压应力(最大压应力7.00MPa),近髋臼窝边缘处骨折面表现为张应力。结论:髋臼记忆内固定系统有良好的耐疲劳与重复使用性,其固定后产生的动态记忆加压应力场,有利于固定髋臼后壁骨折的稳定、预防废用段的发生并促进骨折愈合。
AIM： To study the biomechanical basis of Acetabular Tridimensional Memoryalloy-Fixation System （ATMFS） for treating acetabular posterior wall fracture, and investigate the facilitating effects of dynamic memorial stress of ATMFS for bone healing. METHODS： The experiment was accomplished in Changhai Hospital in January 2006. By three-dimensional （3D） finite element analysis, the biomechanical behavior of ATMFS was emulated and analyzed. The finite element Ba Ⅱ model of ATMFS was divided into 7 946 units and 2 520 nodes. The finite element Bblmodel was divided into 1 787 units. The number of nodes was 623. The element was a unit with 20 nodes, 4 faces. The finite element model of acetabulum was divided into 5 783 units, the number of nodes was 9 863. And the finite element was a 3D unit with 10 nodes, 4 faces. RESULTS： ①When the connector fixated acetabulum, in Ba Ⅱ model, the max compressive and tensile stress of metamorphosed compressive part were 228 MPa and -24.5 Mpa, respectively; in Bblmodel, they were 108 MPa and -4.5 kPa, both far less than its utmost stress and fatigue limit. The initiative memorial bone holding force in Ba Ⅱ model for maintaining axial stability was 196 N, and the longitudinal initiative memorial compression force in Bblmodel was 125.05 N. ②The stress distribution in fixed acetabulum and the medial surface of fracture was even, the stress in most nodes was positive stress, which was identical with physiologic loading （the max compressive stress 7.00 MPa）. The fracture of near acetabular fossa boundary was tensile stress. CONCLUSION： The ATMFS has good anti-fatigue and reuse characters. The dynamic memorial compressive stress field is good for the stability of fixation, enhancement of bone healing and prevention of disusing section.
出处
《中国组织工程研究与临床康复》
CAS
CSCD
北大核心
2007年第13期2462-2465,共4页
Journal of Clinical Rehabilitative Tissue Engineering Research
