Biomechanical study of cannulated screws internal fixation with different spatial distribution in the treatment of PauwelsⅡ femoral neck fractures
- VernacularTitle:不同空间分布空心钉内固定治疗股骨颈PauwelsⅡ型骨折的生物力学研究
- Author:
Wei XIAO
1
;
Hao-ran ZHU
;
Lei ZHANG
Author Information
- Publication Type:Journal Article
- Keywords: femoral neck; Pauwels Ⅱ fracture; finite element analysis; cannulated screw; internal fixation; biomechanics
- From: Journal of Regional Anatomy and Operative Surgery 2025;34(9):789-794
- CountryChina
- Language:Chinese
- Abstract: Objective To analyze the biomechanical characteristics of cannulated screws internal fixation models with different spatial distribution in the treatment of PauwelsⅡ fracture of the femoral neck through finite element analysis.Methods One healthy male volunteer was selected as the research subject.A thin-layer scan from the femoral head to the distal femur of the volunteer was performed using 128-slice spiral CT to preliminarily construct a three-dimensional mesh model of the femur.Through subsequent processing,a cannulated screw internal fixation model conforming to human anatomical characteristics was obtained.A horizontal line was drawn based on the center line of the femoral shaft,and the fracture line was set at the center of the femoral neck with an angle of 50° to the horizontal line to construct the Pauwels Ⅱ femoral neck fracture model.Five kinds of cannulated screw internal fixation models with different spatial distribution were simulated and designed in SolidWorks 2021 software,and the assembly models were imported into Ansys 2021R1 software to establish the finite element model.The stress distribution of the femur and its internal fixator in the five models were evaluated,and the displacement of the femoral neck fracture cross-section in the X,Y,and Z directions,as well as the overall displacement of the femur and the internal fixator were analyzed.Results The stresses of the proximal femur of the five models concentrated below the femoral neck fracture line,and the stress peak of the inverted equilateral triangle configuration was the smallest(19.179 MPa).The total stresses of the internal fixator in the five models all concentrated in the middle region of the ventral cannulated screw at the proximal femur,and the stress peak of the inverted equilateral triangle configuration was the lowest(61.742 MPa).The maximum displacement of the femoral neck fracture cross-section in the X and Y directions of the five models all appeared in the anterior and upper regions of the cross-section,and the displacement of the inverted equilateral triangle configuration was the smallest(X axis:0.446 54 mm,Y axis:0.704 21 mm).The maximum displacement of the femoral neck fracture cross-section in the Z direction of the five models all occurred in the posterior upper part of the cross-section,among which the displacement of the inverted equilateral triangle configuration was the smallest(0.225 62 mm).The overall displacement of the proximal femur of the five models concentrated in the stress-loading area of the femoral head,and the displacement of the inverted equilateral triangle configuration was the smallest(0.721 16 mm).The maximum displacement of the internal fixator of the five models located at the tip of the cannulated screw fixed at the top of the femoral neck near the posterior wall,and the displacement of the inverted equilateral triangle configuration was the smallest(0.686 83 mm).Conclusion Among the five different cannulated screws internal fixation models for Pauwels Ⅱ femoral neck fractures,the inverted equilateral triangle configuration has the best stress dispersion effect,the smallest displacement of fracture end,and the best biomechanical stability.
