不同器械固定股骨干横行骨折的生物力学研究及其临床选用

Biomechanical study and clinical choice of different fixation devices to treat femoral fracture

目的通过比较TiNi记忆合金环抱接骨板(环抱器)、有限接触动力加压接骨板(加压钢板)与交锁髓内钉(交锁钉)治疗股骨干横行骨折的生物力学,为临床选用提供依据。方法 8对模型随机一侧用环抱器和交锁钉固定,对侧用钢板固定,行轴向、三点弯和扭转试验。结果轴向试验:环抱器组应变大于钢板、髓内钉组,后两组相仿;100 N时,各组位移相仿;200～600 N时,环抱器组位移大于钢板、髓内钉组,后两组相仿。三点弯试验:环抱器组桡度较钢板、髓内钉组大,后两组相仿。扭转试验:环抱器、髓内钉两组扭角相仿,钢板组较环抱器组(≥3 N.m)和髓内钉组小。结论环抱器、交锁钉和加压钢板固定股骨干横行骨折的稳定性依次加强,环抱器固定后的轴向微动可促进骨折愈合。

Objective To investigate the biomechanical properties of transverse fractured femurs when fixed by TiNi shape-memory alloy embracing plate（TiNi SMA）,limited-contact dynamic compression plate（LC-DCP） and static interlocking intramedullary nail（SIiN）,respectively,so as to provide the theoretical evidence for orthopedic surgeons in clinical application.Methods Eight pairs of cadaveric femurs were used with one side randomly fixed by TiNi SMA and SIiN and the other side fixed by LC-DCP.Then the axial compression test,three-point bending test,and torsion test were conducted.Results For axial compression test,the strains of TiNi SMA group were greater than those of LC-DCP group and SIiN group（P0.05）,while no significant differences were found between LC-DCP group and SIiN group（P0.05）.The displacements of TiNi SMA group were greater than those of LC-DCP group and SIiN group（P0.05） under the load of 200~600 N,and there were no significant differences between LC-DCP group and SIiN group（P0.05）.For three-point bending test,the displacements of TiNi SMA group were greater than those of LC-DCP group and SIiN group（P0.05）,while no significant differences were found between LC-DCP group and SIiN group（P0.05）.For torsion test,the torsion angels of TiNi SMA group were similar to those of SIiN group（P0.05）,but the torsion angles of LC-DCP group were smaller than those of TiNi SMA group（≥3 N·m）and SIiN group（P0.05）.Conclusions When the fractured femurs are fixed by three internal fixation devices,the stability of TiNi SMA group is weakest,SIiN group being better,and LC-DCP group being best.The axial micromotion in TiNi SMA group can promote the healing of fracture.