尺骨鹰嘴新型交锁髓内钉力学性能的有限元分析和标本实验研究

Novel cross-locking intramedullary nails for olecranon:a finite element analysis and specimen experiments

目的采用有限元仿真和标本实验结合的方式测定新研制的尺骨鹰嘴交锁髓内钉的力学性能, 并探究新型交锁髓内钉(NIN)锥形锁定螺钉使用数量对其固定性能的影响。方法利用Mimics19.0和SolidWorks 2014建立尺骨鹰嘴横形骨折模型, 分别采用克氏针张力带(KTB)和NIN修复;利用Ansys分析KTB、NIN的固定强度。用15例人体尺骨标本构造尺骨鹰嘴横形骨折模型, 并用Instron E10000力学试验机分别对KTB、NIN使用1颗锥形锁定螺钉(NIN-1)和NIN使用3颗锥形锁定螺钉(NIN-3)修复尺骨鹰嘴骨折模型进行力学试验。结果有限元仿真前臂屈曲45°, 受载100 N时, KTB、NIN-1、NIN-3固定尺骨鹰嘴骨折面的最大变形分别为0.131、0.123、0.121 mm。标本试验模拟前臂屈曲45°, KTB、NIN-1、NIN-3的最大破坏载荷分别为(313.38±27.68)、(528.56±53.58)、(871.04±94.95)N, 三组间比较差异有统计学意义(P<0.05), NIN-3的最大破坏载荷大于KTB和NIN-1, 同时NIN-1的最大破坏载荷大于KTB, 两两比较差异均有统计学意义(P<0.05)。结论相比KTB, 采用NIN手术操作更方便, 力学性能更优, 并且NIN-3的力学性能最佳, NIN-1次之。

Objective To determine the mechanical properties of our self-designed novel cross-locking intramedullary nails and the impact of number of conical locking nails on the fixation through a finite element analysis and specimen experiments.Methods Mimics 19.0 and SolidWorks 2014 were used to create transverse fracture models of the olecranon which were subjected to fixation with respectively K-wire tension band(KTB)and our self-designed novel cross-locking intramedullary nails(NIN).The strengths of KTB and NIN fixation were analyzed by Ansys.Fifteen human ulna specimens were used to construct a transverse fracture model of the olecranon;an Instron E10000 mechanical testing machine was used to determine mechanical properties in fixation respectively with KTB,one NIN(NIN-1)and 3 NINs(NIN-3).Results In the finite element analysis,in simulation of the forearm flexed at 45°under a 100 N load,the deformation of the fracture surface of the olecranon in fixation with KTB,NIN-1 and NIN-3 was respectively 0.131 mm,0.123 mm and 0.121 mm.In the specimen experiments,in simulation of the forearm flexed at 45°,the maximum failure loads for fixation with KTB,NIN-1 and NIN-3 were(313.38±27.68)N,(528.56±53.58)N and(871.04±94.95)N,respectively,showing significant differences among the 3 groups(P<0.05).The maximum failure load for NIN-3 fixation was significantly greater than that for KTB or NIN-1 fixation,and the maximum failure load for NIN-1 fixation was significantly greater than that for KTB fixation(P<0.05).Conclusions Compared with KTB fixation,NIN fixation is more convenient in operation and has better mechanical properties.NIN-3 fixation has the best mechanical properties.