股骨颈骨折愈合后不同钉道类型的有限元分析

Finite Element Analysis of Different Screw Path after Femoral Neck Fracture Healing

目的探讨股骨颈骨折愈合取出空心钉内固定后不同钉道类型对股骨近端力学分布的影响,为术后康复和并发症的预防提供理论参考。方法利用64排螺旋CT扫描重建人体股骨近端的三维有限元模型,分别模拟正三角形与倒三角形空心钉内固定方式取出后的股骨近端钉道三维有限元模型,对模型进行加载和仿真计算。比较2种钉道模型与正常股骨模型在同一载荷下的应力分布。结果最大应力均集中在股骨颈下方的股骨距区域。正三角形钉道模型股骨颈应力最大值(11.02 MPa)远远大于倒三角形钉道模型(10.82 MPa)与正常股骨近端模型(10.58MPa)。结论正三角形空心钉内固定取出后会明显造成股骨近端应力升高,在术后康复和功能锻炼时需要密切注意股骨颈骨折的风险。

Objective To investigate the stress distribution of different screw path of proximal femur after femoral neck fracture healing with removal of cannulated screws so as to provide theoretical reference for rehabilitation and pre-vention of complications after surgery.Methods Dimensional finite element model of the human proximal femur was reconstructed by 64-slice spiral CT scan.Finite element model of equilateral triangle and inverted triangle screw path were established respectively.Under the same load and constraint,the von stresses of the femural in different models were compared by the finite element analysis.Results The maximum von stress were concentrated in the region of cal-car under the femoral neck.The maximum von stress of equilateral triangle model （11.02 MPa）was much larger than inverted triangle model（10.82 MPa）and normal proximal femur model （10.58 MPa）.Conclusion The stress of femur neck would increase significantly after equilateral triangle screws were removed.It was needed to pay close attention to risk of femoral neck fracture when did rehabilitation and functional exercises after surgery.