不同内固定方式治疗股骨颈骨缺损骨折的静力学与模态分析  

Static and modal analysis of different internal fixation methods for treating femoral neck fractures with bone defects

作　　者：章浩伟[1] 秦燕韩 刘颖[1] ZHANG Haowei;QIN Yanhan;LIU Ying(School of Health Science and Engineering,University of Shanghai for Science and Technology,Shanghai 200093)

机构地区：[1]上海理工大学健康科学与工程学院,上海200093

出　　处：《北京生物医学工程》2024年第4期352-360,共9页Beijing Biomedical Engineering

摘　　要：目的 探讨不同内固定方式治疗股骨颈骨缺损骨折的静力学特征以及固有和约束模态对内固定的影响。方法 首先基于CT图像建立伴有股骨颈内固定系统(femoral neck system,FNS)和倒三角空心钉(cannulated screw,CS)两种不同内固定装置的股骨颈骨折模型与股骨颈骨缺损骨折模型,然后模拟3倍体重载荷下,不同骨折内固定模型的应力、位移分布及峰值以及模态下的位移峰值、频率以及固有和约束模态振型。结果 两种内固定方式下,股骨颈骨缺损骨折的内固定应力峰值(337.69 MPa,618.58 MPa)显著高于股骨颈骨折模型(149.38 MPa,300.57 MPa),股骨头应力峰值(107.75 MPa,93.78 MPa)与位移峰值(5.244 mm,4.415 mm)也都高于股骨颈骨折模型[(95.73 MPa,85.64 MPa),(4.367 mm,3.478 mm)]。在骨折类型相同的情况下,FNS内固定模型相比CS内固定模型具有更低的位移峰值以及更加均匀的应力分布。模态分析结果显示,振动对于内固定的稳定性有一定影响,约束模态的振型频率范围要小于固有模态。固有模态下FNS的位移峰值较CS降低了6.99%,约束模态下位移峰值降低了14.02%。结论 骨缺损会严重破坏内固定的力学环境,无论是普通骨折模型还是骨缺损骨折模型,FNS固定的静态与动态特性都要优于CS固定。临床治疗中要考虑股骨及内固定器械的固有、约束频率所产生的影响,避免因共振而造成内固定失效等问题。Objective To explore the static characteristics of different internal fixation methods for the treatment of femoral neck bone defect fractures and the effects of natural and constrained modes on internal fixation.Methods Firstly,based on CT images,a femoral neck fracture model and a femoral neck bone defect fracture model were established with two different internal fixation devices,the femoral neck internal fixation system(FNS) and the inverted triangular cannulated screw(CS).Then,the stress,displacement distribution and peak values of different fracture internal fixation models,as well as the displacement peak values,frequencies,and natural and constrained mode shapes under a triple body load were simulated.Results Under the two types of internal fixation methods,the peak stresses of internal fixation for femoral neck bone defect fractures(337.69 MPa,618.58 MPa) were significantly higher than those of femoral neck fracture models(149.38 MPa,300.57 MPa).The peak stresses(107.75 MPa,93.78 MPa) and displacements of the femoral head(5.244 mm,4.415 mm) were also higher than those of femoral neck fracture models [(95.73 MPa,85.64 MPa),(4.367 mm,3.478mm)].In the case of the same fracture type,FNS internal fixation model had lower displacement peak and more uniform stress distribution compared to the CS internal fixation model.The modal analysis results showed that vibration had a certain impact on the stability of internal fixation,and the frequency range of the constrained mode was smaller than the natural mode.The displacement peak of FNS in the natural mode decreased by 6.99% compared with that of CS,and the displacement peak in the constrained mode decreased by 14.02%.Conclusions Bone defects can seriously damage the mechanical environment of internal fixation.Whether it is a common fracture model or a bone defect fracture model,FNS fixation has better static and dynamic characteristics than CS fixation.In clinical treatment,the influence of the inherent and constrained frequencies of the femur and internal fixati

关 键 词：股骨颈骨折 骨缺损 有限元分析 模态分析 内固定 

分 类 号：R318[医药卫生—生物医学工程]