新型股骨颈内固定系统与3枚空心钉加内侧钢板固定青壮年Pauwels Ⅲ型股骨颈骨折的有限元分析

Finite Element Analysis of the new femoral neck internal fixationsystem and three hollow screws plus medial plate fixation for Pauwels Ⅲ femoral neck fractures in young adults

目的采用有限元分析方法比较新型股骨颈内固定系统(FNS)与3枚空心螺钉加内侧钢板固定青壮年PauwelsⅢ型股骨颈骨折的生物力学特性。方法收集一例PauwelsⅢ型股骨颈骨折住院患者(男,35岁)的健侧股骨CT扫描数据,将该股骨CT数据通过数字医学软件建立股骨的三维模型。按照60°骨折线角度对股骨颈进行简化分割,模拟出PauwelsⅢ型股骨颈骨折,在Solidworks2017软件中按照临床上相应的内固定尺寸和手术方案置入模拟的内固定模型于股骨模型中,分为FNS置入和3枚空心钉加内侧钢板置入两种模型,最后使用ANSYS软件进行划分网格、材料赋值和数据计算等步骤,FNS与3枚空心钉加内侧钢板固定后的生物力学稳定性有何差异。结果实验分为2组:a.FNS组,b.空心钉加内侧钢板组。股骨头侧应力峰值分别为:a:126.74Mpa,b:180.11Mpa。内固定应力峰值分别为:a:143.17Mpa,b:214.68MPa。股骨头处位移峰值分别为:a:10.726mm,b:11.278mm。内固定位移峰值分别为:a:10.164mm,b:11.004mm。结论FNS对骨折端固定的力学稳定性优于3枚空心钉加内侧钢板,是青壮年不稳定型股骨颈骨折值得优先考虑的手术固定方式。

Objective In this study,finite element analysis method was used to compare the biomechanical characteristics of femoral neck system(FNS)and three hollow screws combined with medial plate fixation of Pauwels typeⅢfemoral neck fracture,so as to provide reference for the selection of clinical surgical options.Methods The CT scanning data of the healthy femur of a hospitalized patient with Pauwels III femoral neck fracture(male,35 years old)were collected,and the CT data of the femur were used to establish the three-dimensional model of the femur by digital medical software.The femoral neck was simplified and segmented according to the angle of 60°fracture line,and the Pauwels III femoral neck fracture was simulated.In Solidworks 2017 software,the simulated internal fixation model was placed in the femoral model according to the corresponding clinical internal fixation size and surgical scheme,and it was divided into two models,FNS placement and three hollow nails plus medial plate placement.Finally,ANSYS software was used meshing,material assignment and data calculation.What was the difference in biomechanical stability between FNS and three hollow nails plus medial plate fixation.Results The peak stress of femoral head were,a:126.74 Mpa,b:180.11 Mpa.The peak stress of internal fixation were,a:143.17 MPa,b:214.68 MPa.The peak displacement of femoral head were,a:10.726 mm,b:11.278 mm.The peak displacement of internal fixation were,a:10.164 mm,b:11.004 mm.Conclusions FNS for the fixation of the fracture end is better than that of the hollow nail and the medial plate,and the femoral neck system has the advantages of small incision and short timeconsuming in the operation process,which is a preferred surgical fixation method for femoral neck fractures.