LISS、Gamma钉、DHS内固定治疗Evans-Jensen Ⅲ型股骨粗隆间骨折生物力学分析

Biomechanical analysis on LISS,Gamma nail and DHS internal fixation for the treatment of Evans-Jensen type Ⅲ intertrochanteric fractures

目的:探讨LISS、Gamma钉、DHS内固定模式在治疗Evans-JensenⅢ型股骨粗隆间骨折的生物力学差异。方法:收集10例受试者的CT扫描数据,利用软件建立股骨计算机辅助设计(CAD)模型,包括Evans-JensenⅢ型股骨粗隆间骨折的三维有限元分析模型及不同内固定治疗的三维有限元模型(C1为LISS内固定、C2为Gamma钉固定、C3为DHS内固定三维有限元模型),进行内固定的Evans-JensenⅢ型股骨粗隆间骨折三维有限元分析,比较Evans-JensenⅢ型骨折的3种内固定治疗模型的应力集中部位、应力分布及最大位移。结果:C3模型的最大应力值明显大于C1及C2模型(P<0.05),C1模型的最大位移值显著大于C2及C3模型(P<0.05);C3模型股骨近端最大应力值最大,C2模型最小(P<0.05);C1、C2、C3模型股骨近端的水平最大位移、冠状最大位移、轴状最大位移及总位移比较,差异有统计学意义(P<0.05);C1、C2、C3模型骨折断面处应力值及骨折间隙应力值的前外侧、前内侧、后外侧、后内侧比较,差异有统计学意义(P<0.05);C3模型螺钉顶部周围骨质应力值明显高于C1及C2模型(P<0.05)。结论:采用LISS、Gamma钉、DHS内固定治疗Evans-JensenⅢ型股骨粗隆间骨折时,3种治疗方法的生物力学存在一定差异,在临床中可依据患者具体情况选择合适的内固定治疗措施。

Objective： To analyze the biomechanical difference of LISS, Gamma nail and DHS internal fixation in the treatment of type Ⅲ Evans-Jensen intertrochanteric fracture. Methods： CT scan data from 10 subjects were collected. Femoral computer aided design （CAD）model including the three-dimensional finite element model of Evans-JensenⅢ type intertrochanteric fracture, and LISS internal fixation （C1）, Gamma nail fixation （C2）, and DHS intemal fixation （C3） three-dimensional finite element models. The stress distribution and the maximum displacement of the three internal fixation were compared. Results： The maximum stress value of the C3 model was significantly higher than that of C1 and C2 （P〈0. 05）. The maximum displacement value of the C 1 model was significantly higher than that of C2 and C3 （P〈 0. 05）. C3 model had highest maximum displace- ment value, and C2 was the lowest （P〈0. 05）. There were significant differences in proximal femur level of maximum displacement, maximum displacement, maximum coronary axial displacement and total displacement among C1, C2, and C3 models （P〈0. 05）. Significant differences were found in anterolateral, anteromedial, posterolateral and medial posterior fracture stress as well （P〈0. 05）. The bone stress around the screw top in C3 model was significantly higher than that of C1 and C2 models（P〈0. 05）. Conclusion： LISS, Gamma and DHS nail internal fixations had biomechanical difference in the treatment of type Ⅲ Evans-Jensen intertrochan- teric fracture. The appropriate internal fixation measures should be taken according to patient＇s specific situationin clinical practice.