生物型空心松质骨螺钉的力学强度研究  

Mechanical strength of biological canulated cancellous screw

作　　者：史定伟[1] 干耀恺[1] 梁栋科[2] 肖飞[1] 薛文东[1] 孙月华[1] 朱振安[1] 戴尅戎[1] 

机构地区：[1]上海市骨科内植物重点实验室,上海交通大学医学院附属第九人民医院骨科,上海200011 [2]淮阴工学院,江苏省介入医疗器械研究重点实验室,江苏淮安223003

出　　处：《医用生物力学》2013年第5期574-579,共6页Journal of Medical Biomechanics

基　　金：上海市骨科内植物重点实验室建设基金(08DZ2230300);上海市卫生局科研课题(2010134);上海市科委医学引导项目(134119a5500);淮阴工学院江苏省介入医疗器械研究重点实验室开放基金(JR1101);国家自然科学基金资助项目(30801175)

摘　　要：目的研发生物型空心螺钉并评价其力学性能,为今后经螺钉尾部注射富集骨髓干细胞并经螺钉扩散治疗骨折,特别是促进股骨颈骨折术后骨愈合、预防股骨头坏死提供理论基础。方法对用于股骨颈骨折治疗的内固定TC4钛合金空心松质骨螺钉(直径7.3 mm)进行改良,设计研制封堵尾帽,并在长900 mm的空心松质骨螺钉的螺杆上设计侧孔,侧孔沿螺钉轴线排列,第1侧孔距钉尖20 mm,以后每个侧孔间距10 mm,依次为侧孔0～6个不等。侧孔为0的螺钉作为对照,其余分成平行于孔加力A组和垂直于孔加力B组,应用Instron材料试验机对螺钉进行3点弯曲测试,统计分析侧孔的数量及加压方向与螺钉力学强度的关系。结果 (1)平行于孔加力A组,即当螺钉侧孔方向面对受力方向,侧孔数量为0、1、2个时,螺钉受压应变达到3 mm,最大载荷和弹性模量均没有统计学差异;而当侧孔数量增加至3个以上时,最大载荷和弹性模量均出现明显下降,有统计学意义(P<0.05)。(2)垂直于孔加力B组,即当螺钉侧孔方向垂直于受力方向,侧孔数量为0、1、2个时,螺钉受压应变达到3 mm,最大载荷间没有统计学差异(P>0.05),侧孔数量为0、1、2、3个时,螺钉的弹性模量间没有统计学差异(P>0.05);而当侧孔数量增加时,最大载荷(≧3个侧孔)、弹性模量(≧4个侧孔)均出现明显下降,有统计学意义(P<0.05)。(3)当侧孔数≧3个时,垂直于孔加力组螺钉所能承受的最大载荷和弹性模量均高于同等侧孔数目螺钉受到平行于孔加力时的结果(P<0.05)。结论 (1)直径7.3 mm钛合金空心松质骨螺钉的侧孔数目控制在2个以内,对螺钉的力学性能无明显影响;(2)若螺钉侧孔数≧3个,螺钉侧孔方向垂直于载荷方向较平行于载荷方向,能提供更强的力学性能。本研究为今后生物型空心螺钉的临床开发和使用提供了理论依据和支持。Objective To develop a biological canulated screw and evaluate its mechanical properties, so as to provide theoretical basis for the bio-therapy of fracture with enrichment technique of bone marrow stem cells, which could be diffused through the canula, particularly for promoting bone union of femoral neck fracture and preventing avascular necrosis of femoral head. Methods TC4 titanium alloyed canulated cancellous screw （7.3 mm in diameter） commonly used for internal fixation of femoral neck fracture was improved by designing an end sealing plug and side holes in a 900 mm-long canulated screw. The side holes were arranged along the axis of screw, and the first side hole was 20 mm away from the screw tip. The distance between each side hole was10 mm, and the number of side holes ranged from 0 to 5. The screws without holes were tested as control, and the rest were divided into two groups, i. e., group A： force direction parallel to the side hole, group B= force direction perpendicular to the side hole. Three-point bending test on the screw was conducted by using Instron material testing machine, so as to study the relationship between the mechanical strength of the screw and the number of side holes, and the loading direction. Results （1） When the force direction was parallel to the side hole, which was confined within O, 1 or 2, the bending deformation of the screw reached 3 mm, and no differ- ences were found in the maximum loads and elastic modulus of the screw. However, when the number of side holes was increased to 3 or more, a significant reduction in the maximum load and elastic modulus of the screw was found （ P 〈 0.05 ）. （2） When the force direction was perpendicular to the side hole, which was confined within 0,1 or 2, and the bending deformation of the screw reached 3 mm, no significant differences were found in the maximum loads of the screw. While no significant difference was found in the elastic modulus of the screw when the side hole was 0, 1, 2 and 3. With an increase in the nu

关 键 词：内固定 空心螺钉 骨折 力学特性 

分 类 号：R318.01[医药卫生—生物医学工程]