摘要
目的:建立枢椎的三维有限元(FE)模型,探讨在前、后方不同载荷下齿突的不同损伤机制和骨折类型。方法:对一例新鲜枢椎标本进行CT扫描,层厚1 mm,扫描图像转换后输入微机,通过软件PRO／E重建枢椎的三维立体模型,再转入有限元软件MARK并赋予此模型物理材料属性,然后模拟齿突骨折的受力条件,在齿突中性矢状面对齿突施加不同角度的载荷,分析各种条件下枢椎模型的应力、应变分布,探讨相应条件下可能导致的枢椎齿突骨折类型。结果:(1)对于齿突前部斜向后下方载荷,应力集中区从齿突前上部斜贯穿至后下部;对于齿突前部斜向后上方载荷,应力集中区从齿突前下部斜贯穿至后上部;齿突腰部始终保持高应力;(2)在齿突后部载荷下,其应力集中情况与前部载荷相似,不过应力集中区位置有所偏下。结论:(1)在齿突中性矢状面,齿突前部载荷容易导致齿突腰部发生断裂,形成枢椎齿突Ⅱ型骨折,也可能导致基底部发生断裂,形成枢椎齿突Ⅲ型骨折;(2)齿突后部载荷更容易导致基底部发生断裂,形成枢椎齿突Ⅲ型骨折。
Objective: To set up the finite element(FE) model of axis and analyse the injury mechanisms and fracture patterns of odentoid under anterior and posterior load. Methods: One intact fresh adult cadaveric axis was scanned by CT with 1mm interval. The picture files of CT were transferred to PC and the three-dimensional coordinates were gotten. Those information were utilized to establish the stereoscopic model of axis through the software of PRO/E. Then the model were transmitted to the program of Mark, through which material property was yielded and elements was compartmentalized. According to the clinical characteristics of odontoid fracture, various boundary conditions and loads (on the symmetrical area of axis) were endowed. The theoretical stress distribution of axis was calculated, from which the mechanisms of odentoid fractures were analyzed. Results: The results of calculations showed that no matter what direction of loads was given, the largest Von Mises stress focused on the middle of odontoid process, as well as the maximal stress region varied with the directions of loads, and the posterior loads resulted in more stress concentration on the base of odontoid process than the anterior loads did. Conclusions: On the symmetrical area of axis, the anterior loads are inclined to arouse both type Ⅱ and type Ⅲ odontoid fracture, while the posterior loads are more inclined to arouse the latter.
出处
《中国临床解剖学杂志》
CSCD
北大核心
2005年第1期96-99,共4页
Chinese Journal of Clinical Anatomy
基金
国家自然科学基金(30371149)
关键词
枢椎
齿突
有限元
骨折
应力
axis
odontoid process
finite element
fracture
stress
