scholarly journals Influence of the proximal screws of buttress plates on the stability of vertical femoral neck fractures: a finite element analysis

2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Shi Zhan ◽  
Dajun Jiang ◽  
Jian Xu ◽  
Ming Ling ◽  
Kai Yang ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Neck ◽  
Biomechanical Properties ◽  
Femoral Neck Fractures ◽  
Cannulated Screws ◽  
Element Analysis ◽  
Proximal Screw ◽  
Buttress Plate ◽  
Plate System

Abstract Background The treatment of vertical femoral neck fractures (vFNFs) in young patients remains challenging, with a high complication rate by using traditional techniques. The use of cannulated screws (CSs) combined with a buttress plate represents an alternative approach for treating vFNFs. However, the biomechanical influence of the use or non-use of the proximal screws of buttress plates on vFNFs stability remains unclear. This study aims to analyse the biomechanics of buttress plate fixation with or without the use of proximal screws through finite element analysis (FEA) to further understand this approach. Methods We built five vFNFs (Pauwels angle 70°) finite element models treated using three cannulated screws (CS group) or three cannulated screws plus a locking buttress plate (buttress group). In the buttress group, use or non-use of proximal screws was carried out on two types of plates (4-hole & 6-hole). The following seven parameters were analysed to compare biomechanical properties of the five models: the stiffness; the maximal stress of the plate system (plate and screws), CSs and bone (MPS, MCS, MBS); the maximal displacement of internal fixations (plate system & CSs) and bone (MIFD, MBD); and the maximal relative displacement of interfragments (MID). Results Compared with CS model, the buttress models exhibited improved biomechanical properties, with increased stiffness and decreased MCS, MBS, MIFD, MBD and MID. The models fixed using buttress plates combined with a proximal screw showed greater stiffness (+ 3.75% & + 8.31% vs + 0.98% & + 4.57%) and MPS (795.6 & 947.2 MPa vs 294.9 & 556.2 MPa) values, and smaller MCS, MBS, MIFD, MBD and MID (− 3.41% to − 15.35% vs − 0.07% to − 4.32%) values than those using the same length plates without a proximal screw. Conclusions Based on the FEA results, buttress plates can improve construct mechanics, help to resist shear force and prevent varus collapse; under the modelling conditions, the use of a proximal screw on buttress plate may be a key technical feature in improving anti-shearing ability; additionally, this screw may be essential to reduce stress and prevent re-displacement of cannulated screws and fracture fragments.

Finite element analysis of different screw constructs in the treatment of unstable femoral neck fractures

Injury ◽  
2020 ◽  
Vol 51 (4) ◽  
pp. 995-1003 ◽  
Author(s):  
Jiantao Li ◽  
Menglin Wang ◽  
Jianfeng Zhou ◽  
Hao Zhang ◽  
Lianting Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Neck ◽  
Femoral Neck Fractures ◽  
Element Analysis

scholarly journals Medial anatomical buttress plate in treating displaced femoral neck fracture a finite element analysis

Injury ◽  
2019 ◽  
Vol 50 (11) ◽  
pp. 1895-1900
Author(s):  
Jia Li ◽  
Pengbin Yin ◽  
Licheng Zhang ◽  
Hua Chen ◽  
Peifu Tang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Element Analysis ◽  
Neck Fracture ◽  
Buttress Plate

scholarly journals The Effect on the Fracture Healing following Femoral Neck Shortening after Osteoporotic Femoral Neck Fracture Treated with Internal Fixation: Finite Element Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Xiao Yu ◽  
Peng-ze Rong ◽  
Qing-jiang Pang ◽  
Xian-jun Chen ◽  
Lin Shi ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Concentration ◽  
Femoral Neck ◽  
Femoral Neck Fracture ◽  
Maximum Stress ◽  
Fracture Site ◽  
Cannulated Screws ◽  
Element Analysis ◽  
Neck Fracture

Objective. To evaluate the stress status of fracture site caused by femoral neck shortening and to analyze the stress of fracture site and the implants from the finite element point of view. Methods. CT scan data of hip of a normal adult female were collected. Three-dimensional reconstruction MICs and related module function simulation was used to establish the postoperative shortening model of femoral neck fracture with Pauwels   angle > 50 ° , which was treated with cannulated screws. The models were divided into four groups: normal femoral neck, shortening in 2.5 mm, shortening in 7.5 mm, and shortening in 12.5 mm. The finite element analysis software msc.nastran2012 was used, and the data of maximum stress and stress nephogram of fracture site and implants were carried out. Results. From normal femoral neck to shortening in 12.5 mm of the femoral neck, the maximum tensile stress increased gradually in the fracture site above the cannulated screws while compressive stress decreased gradually in the fracture site below the cannulated screws, and the maximum stress of the cannulated screws increased gradually with obvious stress concentration at the screw holes in the fracture site, and the peak value of stress concentration was about 179 MPa. Conclusion. The biomechanical environment of the fracture site changed by femoral neck shortening. With the increasing of femoral neck shortening, the stress of the fracture site and implants would be uneven; then, the stability of fracture site would become worse, and the possibility of implant sliding or even breakage would be increased.

scholarly journals Biomechanical Evaluation of Reconstruction of Calcar Femorale Structure for Femoral Neck Fractures: A Comparative Finite Element Analysis

2021 ◽  
Author(s):  
Zhi-Hao Gao ◽  
Jian-Xiong Ma ◽  
Ying Wang ◽  
Bin Lu ◽  
Hao-Hao Bai ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Femoral Neck ◽  
Internal Fixation ◽  
Femoral Neck Fracture ◽  
Biomechanical Properties ◽  
Control Group ◽  
Element Analysis ◽  
Neck Fracture ◽  
Reconstruction Nail

Abstract BackgroundThe optimum internal fixation approach for femoral neck fracture therapy is still debated, and there are few studies on calcar femorale repair following femoral neck fracture. The biomechanical properties of various internal fixation systems can be adequately studied using the finite element method. The goal of this work was to use finite element analysis to examine the biomechanical parameters of Pauwels type III femoral neck fractures under various calcar femorale repair nailing procedures.MethodThe finite element approach was used to numerically investigate the calcar femorale reconstruction method for femoral neck fracture repair. A control group with standard inverted triangle nail placement and internal fixation models with calcar femorale reconstruction nails of 150, 155, and 160 degrees, respectively, were constructed. The four groups of models' von Mises stress and displacement distributions are evaluated and compared.ResultsIn the control group and three calcar femorale reconstruction nail angle models, the maximum stress of femur was (MPa): 106.605, 87.317, 147.691, and 102.072 respectively; The peak stress of four kinds of internal fixation were (MPa): 315.121, 228.819, 198.173 and 208.798. In the control group and three calcar femorale reconstruction nail angle models, the maximum displacement of the femur was (mm): 13.19, 13.183, 12.443, and 12.896 respectively; The displacement peaks of the four internal fixations were (mm): 12.646, 12.625, 11.932 and 12.347.ConclusionsAccording to the results of finite element analysis, the biomechanical performance of calcar femorale reconstruction nail with 150 ° is excellent, which is helpful to the reconstruction of calcar femorale structure. This nail placement method can achieve better biomechanical properties. The results of this study can provide a theoretical reference for clinical practice.

Sign in / Sign up

Export Citation Format

Share Document