【作者】 杨晶；

【导师】 闫金成；

【作者基本信息】 河北医科大学 ， 外科学， 2017， 硕士

【摘要】 目的:胫骨为小腿双骨之一,位于小腿的内侧,对支持体重起重要作用,为小腿骨中主要承重骨。胫骨骨折是最常见的长骨骨折,其发生率约26/10万。男性胫骨骨折概率约比女性高3倍,病人的平均年龄大约是37岁。在男性中胫骨骨折常见于青少年,一般都是高能量创伤,如机动车事故。由于胫骨解剖结构及周围软组织的特异性及多为暴力损伤,导致胫骨骨折多为开放性或粉碎性骨折,且容易发生感染、骨折延迟愈合或不愈合,最终导致骨髓炎,骨坏死,最终需行骨延长治疗甚至截肢,因此,严重的开放性胫腓骨骨折的临床治疗面临着许多的难题。随着对胫骨生物力学研究的深入和骨科的手术技术的极速发展,极大改善了胫骨骨折预后,提高了患者生活质量。目前,对于严重的胫腓骨开放骨折的治疗,大都主张早期应用外固定器有效固定骨折端,为闭合创面提供有利条件,二期视软组织条件再行内固定治疗或使用外固定器终末固定。本研究的目的是对两种不同弹性模量的外固定架进行生物力学测试,探讨两种不同弹性模量的外固定架对胫骨骨折应力的影响,为临床选择合适的外固定材料及装置提供理论依据。方法:选择8根成人尸体胫骨,将胫骨中段横行锯断,制作胫骨骨折模型,分为A、B两组。将骨折标本解剖复位后A组以铝合金材料外固定架(高弹性模量,弹性模量为110 GPa)固定,B组以碳纤维树脂材料外固定架(低弹性模量,弹性模量为11.4 GPa)固定。然后将模型分别置于生物力学实验机上,分别行轴向压缩压力实验、扭转实验及四点弯曲实验,对这两种材料的外固定架进行生物力学研究。结果:1轴向压缩压力实验结果:在轴向压缩压力试验中,加载压力为0-1000N。在这个载荷范围内,骨折端的位移与加载的压力曲线为直线,反应这两者之间为线性关系,两组标本位移均随压力的增大而增加,在最大轴向压力下,高分子材料外固定组的位移为:10.164±0.090,传统金属外固定架组的位移为:9.633±0.042.两组不同材料外固定架骨折模型的位移差异有统计学意义(Z=-8.627,P<0.01)。高分子外固定架组位移比传统金属外固定架组大。高分子材料外固定架组的刚度为:142.139±31.322,传统金属外固定架组的刚度为108.310±13.019,两组不同材料外固定架的刚度差异无显著统计学差异(Z=-1.443,P=0.149>0.05)。2扭转实验结果:在扭转试验中,加载的扭矩为0-4N.m。在这个载荷范围内,骨折端的位移与加载的压力曲线为直线,反应这两者之间为线性关系,两组标本扭转角度均随扭矩的增大而增加。在最大扭矩下,高分子材料外固定架组的扭转角度为:8.302±0.031,传统金属外固定架组的扭转角度为:6.161±0.052.两组不同材料外固定架骨折模型差异有明显统计学意义(Z=-8.627,P<0.01)。高分子外固定支架组扭转角度比传统金属外固定架组大。高分子材料外固定架组的刚度为:1.712±0.243,传统金属外固定架组的刚度为1.446±0.530,两组不同材料外固定架的刚度差异无显著统计学差异(Z=-0.577,P=0.564>0.05).3四点弯曲实验结果:在四点弯曲实验中,加载的压力为0-1000N。在这个载荷范围内,骨折端的位移与加载的压力曲线为直线,反应这两者之间为线性关系。两组标本位移均随压力的增大而增加。在最大压力作用下,高分子材料外固定架组的位移为:2.909±0.292,传统金属外固定架组的位移为:2.256±0.052,两组不同材料外固定架骨折模型差异有明显统计学意义(Z=-8.617,P<0.001)。高分子外固定支架组位移比传统金属外固定架组大。高分子材料外固定架组的刚度为:496.647±63.454,传统金属外固定架组的刚度为547.577±35.944,两组不同材料外固定架的刚度差异无显著统计学差异(Z=-1.732,P=0.083>0.05)。结论:使用传统金属外固定架与高分子材料外固定架固定胫骨骨折均具有良好的稳定性。使用高分子材料外固定架相比较与传统金属外固定架更有利于轴向应力传导,更符合生物力学的要求,从而可能有效避免应力遮挡效应,促进骨折愈合,同时可以减少旋转力矩,使骨折端更为稳定,而且还能够在一定程度上减小弯曲载荷引起的钉道应力集中现象,可能减少钉道周围骨质吸收或半针松动等临床使用外固定架并发症。因此,其力学性能更佳,从生物力学角度可以推广使用。更多还原

【Abstract】 Objective: Tibial,as one of the shinbone,located in the medial leg,plays an important roles on upper weight,as the main load-bearing bone in the leg.Tibial fractures are the most common long bone fractures with an incidence of about 26/10 0000.Male tibial fracture probability is 3 times higher than women,the average age of the male patients is about 37 years old.Fractures of the tibia in men are common in young people and are generally high energy trauma,such as motor vehicle accidents.Because of the anatomical structure of the tibia and the specificity of the surrounding soft tissue,and the fractures mostly caused by violent injure,Tibial fractures are mostly open or comminuted fractures,and prone to infection,delayed union or nonunion,and eventually lead to osteomyelitis,bone necrosis,and ultima need tobone extension treatment or even amputatio.Therefore,the clinical treatment of severe open fractures of the tibia and fibula is confronted with many difficulties.With the deeply research on the biomechanics of the tibia and the rapid development of the surgical technique in the Department of orthopedics,the prognosis of the tibial fractures has been greatly improved and the quality of life of the patients has been improved.At present,for the treatment of severe open fractures of tibia and fibula,most advocate that the external fixator can effectively fix the fracture end in the early time,which provides favorable conditions for closed wound,the second stage according to the soft tissue conditions to choose the internal fixation or external fixator as the final fixation.The objective of this study was to explore the effects of external fixation systems with two different modulus of elasticity on the stress,and discuss its distribution at tibial fracture through biomechanical testing,to provide theoretical basis for selecting suitable external fixation materials and devices.Methods: 8 sets of adult cadaveric tibia were selected,and the middle of tibias was sawn with an electric saw to form tibia facture models.After anatomic reduction,the fracture samples were fixed with different external fixators group.A group:high elastic modulus(elastic modulus of 110 GPa)which was made of aluminum alloy material,B group :the low elastic modulus(elastic modulus of 11.4 GPa)made of carbon fiber resin material.Then the model is placed on the biomechanics experiment machine,with a line respectively axial compression stress,torsion experiment and four-point bending experiments,of the two kinds of material of external fixator for biomechanical research.Results:1 Axial compression pressure experimental results:In the axial compression stress test,the load pressure is 0-1000 N.Within the scope of the load,the fracture displacement and load pressure curve of straight line,reacted a linear relationship between the two groups.Two groups of specimens displacement increases along with the increase of pressure.Under the maximum axial pressure,the displacement of polymer external fixation group was10.164±0.090 mm,the displacement of traditional metal external fixator group was9.633 ± 0.042 mm.The displacement of two groups of different materials of external fixator fracture model difference was statistically significant.(Z=-8.627,P<0.01).The stiffness of the polymer external fixator group was142.139±31.322,and the stiffness of the traditional metal external fixator group was 108.310±13.019,and there was no significant difference in the stiffness of the external fixator between the two groups(Z=-1.443,P=0.149>0.01).2 Torsion test results:in the torsion test,The load torque was 0-4N.m.Within the scope of the load,the fracture roration and load torque curve of straight line,reacted a linear relationship between the two groups.Two groups of specimens rotation increases along with the increase of torque.Under the maximum torque,the rotation of polymer external fixation group was 8.302±0.031,the rotation of traditional metal external fixator group was 6.161±0.052.The ratation of two groups of different materials of external fixator fracture model difference was statistically significant(Z=-8.617,P<0.01).The stiffness of the polymer external fixator group was 1.712±0.243,and the stiffness of the traditional metal external fixator group was 1.446±0.530,and there was no significant difference in the stiffness of the external fixator between the two groups(Z=-0.577,P=0.564>0.05).3 Four point bending test results:in the four point bending test,The load pressure was 1000 N.Within the scope of the load,the fracture dispiacement and load pressure curve of straight line,reacted a linear relationship between the two groups.Two groups of specimens dispiacement increases along with the increase of pressure.Under the maximum pressure,the dispiacement of polymer external fixation group was2.909±0.292,the dispiacement of traditional metal external fixator group was 2.256±0.052.The dispiacement of two groups of different materials of external fixator fracture model difference was statistically significant(Z=-8.617,P<0.001).The stiffness of the polymer external fixator group was 496.647±63.454,and the stiffness of the traditional metal external fixator group was 547.577±35.944,and there was no significant difference in the stiffness of the external fixator between the two groups(Z=-1.732,P=0.083>0.05).Conclusion: The use of traditional metal external fixator and polymer external fixator for the treatment of tibial fractures both have good biomechanical stability.The use of polymer materials in the treatment of open tibial fractures with external fixation compared with traditional metal external fixation,more conducive to stress conduction,meet the biodynamical requirement,which can effectively avoid stress shielding effect,promote fracture healing.At the same time can reduce the rotation torque,make the fracture is more stable,but also To a certain extent,reduce the bending load caused by the stress concentration phenomenon.It may reduce the bone absorption around the nail or half needle loose,which are the complications of clinical use of external fixator.Therefore,its mechanical performance is better,can promote the use from the Angle of biomechanics.更多还原