带锁髓内钉中棒槌形高螺纹锁钉与通用锁钉抗弯强度及应力分布的比较

发布时间：2018-11-18 19:23

【摘要】：背景:目前带锁髓内钉成为治疗四肢骨折的主要方法之一,但是常见的带锁髓内钉多为静力型带锁髓内钉,会出现断钉、退钉等现象,这些都跟带锁髓内钉中的锁钉强度有关,因而课题组设计了一种新型棒槌形高螺纹锁钉,并研究其力学特性。目的:测量棒槌形高螺纹锁钉的抗弯曲强度,分析其应力分布状况,对其生物力学性能进行测评,为其临床应用提供理论依据。方法:通过三点弯曲力学实验测量棒槌形高螺纹锁钉与通用锁钉的抗弯曲强度,运用有限元法模拟胫骨中段横行骨折,分析2种不同锁钉在胫骨骨折中的受力及应力分布情况。结果与结论:(1)三点弯曲实验中,棒槌形高螺纹锁钉在跨距20 mm和30 mm时的平均最大载荷分别为3.52 k N和1.81 k N,均比通用锁钉承受的载荷大;(2)有限元分析中,棒槌形高螺纹锁钉的平均最大位移与平均最大应力值均比通用锁钉小,且应力相对较分散;(3)使用棒槌形高螺纹锁钉的带锁髓内钉模型的平均最大应力值和最大轴向位移分别为131 MPa和3.27 mm,而使用通用锁钉的带锁髓内钉模型分别为162 MPa和4.07 mm;棒槌形高螺纹锁钉的平均最大应力值和最大轴向位移分别为26.5 MPa和0.323 mm,通用锁钉分别为34.3 MPa和0.407 mm;(4)结果表明,棒槌形高螺纹锁钉的抗弯曲强度较高,能够使应力相对分散,提高其抗疲劳强度,锁钉不易发生疲劳断裂。
[Abstract]:Background: at present, interlocking intramedullary nail has become one of the main methods in the treatment of extremities fracture. However, the common interlocking intramedullary nail is mostly static interlocking intramedullary nail, which will appear the phenomenon of broken nail and unlocking nail, all of which are related to the strength of locking nail in interlocking intramedullary nail. Therefore, a new type of bar-mallet high-thread locking nail is designed and its mechanical properties are studied. Objective: to measure the bending strength and stress distribution of high thread locking nail, and to evaluate its biomechanical properties, and to provide a theoretical basis for its clinical application. Methods: the bending strength of the bar high thread locking nail and the common locking nail were measured by three point bending mechanics experiment. The finite element method was used to simulate the transverse fracture of the middle tibia, and the stress distribution of the two kinds of locking nails in the tibial fracture were analyzed. Results and conclusions: (1) in the three-point bending experiment, the average maximum loads of high thread locking nails with bar and high thread at span 20 mm and 30 mm were 3.52 KN and 1.81 KN, respectively, which were larger than those of common locking nails; (2) in the finite element analysis, the average maximum displacement and the average maximum stress of the high thread locking nail are smaller than those of the common locking nail, and the stress is relatively dispersed; (3) the average maximum stress value and maximum axial displacement of the interlocking intramedullary nail model are 131 MPa and 3.27 mm, respectively, and the average maximum stress value and maximum axial displacement of the interlocking intramedullary nail model are 162 MPa and 4.07 mm;, respectively. The average maximum stress value and maximum axial displacement of high thread locking nail are 26.5 MPa and 0.323 mm, respectively, which are 34.3 MPa and 0.407 mm;, respectively. (4) the results show that the bending strength of high thread locking nail is higher, and the stress can be dispersed relatively, the fatigue strength of lock nail is improved, and fatigue fracture of lock nail is not easy.
【作者单位】：天津理工大学;天津市第四中心医院骨科;
【基金】：天津市卫生局科研项目(09ky08)~~
【分类号】：R687.3

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