股骨颈动力交叉钉系统内固定植入物安放位置的力学差异分析与临床应用

Mechanical difference of placement position of femoral neck system internal solid implants and clinical implication

目的利用三维重建方法建立股骨颈动力交叉钉系统内固定有限元模型,比较植入物不同置入位置对内固定效果差异的影响。方法分别建立植入物处于股骨中上三分之一处,股骨中心以及股骨中下三分之一处,股骨中心沿矢状面前三分之一处,股骨中心沿矢状面后三分之一处,5种股骨颈动力交叉钉系统内固定有限元模型,比较在这5种位置下,股骨颈动力交叉钉系统内固定系统的生物力学差异。结果应力集中在主钉与防旋螺钉的交界处,锁定螺钉钉体,锁定螺钉与钢板的交界处。当植入物置于股骨中心处时,整个内固定系统所受到的最大应力值为14.29 MPa(1 MPa=7500 mmHg),整个内固定系统的位移值为9.07 mm,将植入物安装到股骨中心下方三分之一处时,内固定系统承受的最大载荷比植入物位于中心位置时大256.63%。结论当植入物处于股骨中间位置时,该内固定系统生物力学稳定性更好。

Objective The finite element model of femoral neck system internal fixation was established by three-dimensional reconstruction method,and the influence of different implant positions on the effect of internal fixation was compared.Methods Establish the implants in the upper third of the femur,the center of the femur and the lower third of the femur,the center of the femur along the anterior third of the sagittal plane,and the center of the femur along the posterior third of the sagittal plane.In this section,five finite element models of the internal fixation of the femoral neck dynamic cross nail system are compared to compare the biomechanical differences of the internal fixation system of the femoral neck dynamic cross nail system under these five positions.Results The main stress concentration areas appear at the junction of the main nail and the anti-rotation screw,the locking screw body,the junction of the locking screw and the steel plate,and The shaft of the femur.In the five finite element models the overall maximum stress values of the entire internal fixation system are 38.68,40.07,14.29,13.37,24.06 MPa(1 MPa=7500 mmHg),respectively.The maximum displacement is 6.67,17.62,9.07,0.68,14.76 mm,respectively.Conclusion When the implant is in the middle of the femur,the biomechanical stability of the internal fixation system is better.