4种内固定方式固定Pauwels Ⅲ型股骨颈骨折的有限元分析

The finite element analysis offour internal fixation methods for Pauwels type Ⅲ femoral neck fracture

目的利用有限元法分析一种新型髄内固定装置与三种传统内固定装置在Pauwels Ⅲ型股骨颈骨折固定中的生物力学特性差异,为该新型内固定装置有效性提供理论依据。方法针对PauwelsⅢ型股骨颈骨折特点,设计了一种新型股骨颈骨折内固定装置通过有限元分析方法,建立4种内固定治疗Panwels Ⅲ型股骨颈骨折有限元模型[a:空心螺钉、b:动力髋螺钉(DHS)、c:股骨近端锁定板、d:新型内固定]。在580N的栽荷条件下,研究四种内固定模型的股骨应力大小和位移大小,结果580N栽荷下,四种内固定方式模型股骨位移峰值由小至大分别为:新型内固定4.24 mm、股骨近端锁定钢板4.31 mm、DHS4.60mm、三枚空心螺钉6.84 mm;股骨所受最大应力峰值由小到大分别:DHS 29.125 MPa、三枚空心螺钉32.698 MPa、股骨近端锁定板33.447 MPa、新型内固定39.86 MPac结论在Pauwels Ⅲ型股骨颈骨折行内固定时;3枚空心螺钉在防旋作用上具有优势,但稳定性较差;DHS和股骨近端锁定钢板稳定性较好,但应力相对集中;新型内固定在生物力学特性上是一种较佳的固定方式。

Objective To analyze the biomechanical characteristics of a new type of intramedullary internal fixation device and three traditional internal fixation devices in the fixation of PauweLs type Ⅲ femoral neck fracture by finite element method,to provide a theoretical basis for the effectiveness of the new internal fixation device.Methods According to the characteristics of Pauwels type Ⅲ femoral neck fracture,a new type of internal fixation device for femoral neck fracture was designed.Through the finite element analysis method,establish four kinds of internal fixation treatment Pauwels Ⅲ femoral neck fracture finite clement model a:hollow screw,b:DHS(dynamic hip screw),c:proximal femoral locking plate,d:(new internal fixation).Under the load condition of 580N,the femoral stress and displacement of the four internal fixation models were studied.Results The peak values of femoral displacement of the four internal fixarion models under 580N load were as follows:d-new internal fixation:4.24 mm,c-proximal locking plate of the femur:4.31 mm,b-DHS:4.60 mm,a-Three hollow screws:6.84 nim;the maximum stress peak of the femur is from small to large:b-DHS:29.125MPa,a-three hollow screws:32.698 MPa,c-proximal femoral locking plate:33.447 MPa,d-New internal fixation:39.86 MPa.Conclusion When Pauwels type Ⅲ femoral neck fracture is treated with internal fixation;three cannulated screws have advantages in anti-rotation,but the stability is poor;DHS and proximal femoral locking plate are stable,but the stress is relatively concentrated;new internal fixation is a better fixation method in terms of biomechanical properties.