股骨骨折内固定金属接骨板的生物力学性能研究

发布时间：2018-01-08 01:34

本文关键词：股骨骨折内固定金属接骨板的生物力学性能研究　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着生物学固定理念的不断完善,锁定加压接骨板被广泛应用于骨折内固定治疗。与过分强调解剖复位的坚强内固定相比,生物学固定(弹性固定)允许骨折断端存在一定程度的微动,并认为微动能促进骨痂形成,进而诱导骨折的间接愈合。间接愈合过程对骨折端的力学环境极为敏感,任何不适宜的应力都可能导致骨折延迟愈合甚至不愈合等临床并发症。内固定系统的稳定性是影响骨折端力学环境的重要因素之一,而接骨板本身的设计参数和力学性能及接骨板在临床手术中的固定方式等诸多因素对内固定系统的稳定性均有一定程度的影响。因此,有必要从骨折愈合的角度研究这些因素对内固定系统的影响,研究结果可为临床内固定手术操作提供一定参考,也可为接骨板的优化设计提供理论依据。本文通过建立股骨干中段横形骨折内固定系统的有限元模型,采用数值模拟方法,以骨折块应变理论为基础,模拟了骨折愈合早期的动态愈合过程,考察了接骨板固定参数(植入螺钉数量、固定位置、螺钉预紧力等)、接骨板材料和长度对骨折愈合过程的影响,分析了骨折间隙与接骨板材料和长度的匹配关系。主要结果和结论总结如下:(1)接骨板的固定参数会显著影响骨折的愈合过程。螺钉预紧力对骨折愈合中骨痂发育、股骨和接骨板上的应力分布均无显著影响,但股骨上螺钉孔处的最大应力随螺钉预紧力增大而增大;采用8孔锁定加压接骨板固定股骨干横形骨折时,骨折线两侧的骨折块上应植入的螺钉数量不能低于3枚;邻近骨折线的两枚螺钉对骨折愈合的影响最显著,必须固定。(2)就固定效果而言,骨折间隙与金属接骨板的弹性模量呈负相关。不锈钢接骨板的最佳固定骨折间隙为1-2 mm,纯钛接骨板的最佳固定骨折间隙为2-3 mm,镁合金接骨板的最佳固定骨折间隙为4-5 mm:相同材质的金属接骨板,当骨折间隙较大时,应选择板长较长的接骨板,更有利于为骨折愈合后期提供足够的固定稳定性。(3)不锈钢、纯钛和镁合金三种金属接骨板在骨折愈合早期的应力遮挡率均较高,无明显差异,接骨板材料主要通过影响骨痂弹性模量而对应力遮挡率产生影响。
[Abstract]:With the improvement of biological fixation concept, locking compression plate has been widely used in the treatment of fracture internal fixation, compared with the rigid internal fixation with too much emphasis on anatomical reduction. Biological fixation (elastic fixation) allows a certain degree of fretting at the fracture end and suggests that microkinetic energy promotes callus formation. The indirect healing process is very sensitive to the mechanical environment of the fracture end. Any inappropriate stress may lead to clinical complications such as delayed fracture healing or even nonunion. The stability of internal fixation system is one of the important factors that affect the mechanical environment of fracture end. However, the design parameters and mechanical properties of the plate itself, as well as the fixation mode of the plate in the clinical operation have a certain degree of influence on the stability of the internal fixation system. It is necessary to study the influence of these factors on the internal fixation system from the angle of fracture healing. It can also provide theoretical basis for the optimal design of the plate. In this paper, the finite element model of the internal fixation system of femoral shaft transverse fracture is established, and the method of numerical simulation is adopted, which is based on the strain theory of fracture block. The dynamic healing process in the early stage of fracture healing was simulated, and the effects of plate fixation parameters (number of screws, fixation position, screw pretension force, material and length of plate) on fracture healing were investigated. The matching relationship between the fracture gap and the material and length of the plate is analyzed. The main results and conclusions are summarized as follows: 1). The fixation parameters of the plate can significantly affect the healing process of the fracture. There was no significant effect on the stress distribution in the femur and the plate, but the maximum stress at the hole of the screw increased with the increase of the pretightening force of the screw. When the femoral shaft transverse fracture was fixed with 8-hole locking compression plate, the number of screws should not be less than 3 on both sides of the fracture line. The two screws adjacent to the fracture line have the most significant effect on fracture healing and must be fixed. The best fixation gap of stainless steel plate was 1-2 mm, and that of pure titanium plate was 2-3 mm. The best fixation gap of magnesium alloy plate is 4-5 mm. When the fracture gap is large, the long plate should be chosen. It is more favorable to provide enough fixation stability for fracture healing. Stainless steel, pure titanium and magnesium alloy metal plates have higher stress shielding rate in the early stage of fracture healing, but there is no significant difference. The plate material mainly affects the stress shielding rate by influencing the elastic modulus of callus.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R687.3;R318.01

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