Finite element analysis informed variable selection for femoral fracture risk prediction

Author(s):  
Mark Taylor ◽  
Marco Viceconti ◽  
Pinaki Bhattacharya ◽  
Xinshan Li
2015 ◽  
Vol 15 (03) ◽  
pp. 1530003 ◽  
Author(s):  
SVEN VAN DEN MUNCKHOF ◽  
ALI ASADI NIKOOYAN ◽  
AMIR ABBAS ZADPOOR

Femoral fracture risk prediction is a necessary step preceding effective pharmacological intervention or pre-operative planning. Current clinical methods for fracture risk prediction rely on 2D imaging methods and have limited predictive value. Researchers are therefore trying to find improved methods for fracture prediction. During last few decades, many studies have focused on integration of 3D imaging techniques and the finite element (FE) method to improve the accuracy of fracture assessment techniques. In this paper, we review the recent advances in FE and other techniques for predicting the risk of femoral fractures. Based on a number of selected studies, the different steps that are involved in generation of patient-specific FE models are reviewed with particular emphasis on the fracture criteria. The inaccuracies that might arise due to the imperfections of the involved steps are also discussed. It is concluded that compared to image- and geometry-based techniques, FE is a more promising approach for prediction of fracture loads. However, certain technological advancements in FE modeling protocols are required before FE modeling can be recruited in clinical settings.


Author(s):  
Yangyang Cui ◽  
Dingding Xiang ◽  
Liming Shu ◽  
Zhenhua Liao ◽  
Zhilin Zhang ◽  
...  

Numerical simulation of the proximal femur could provide an effective approach to predict the femoral fracture risk. However, most of the extant numerical simulations are static simulations, which cannot accurately reflect the dynamic growth process of cracks. In this study, the dynamic simulation by incremental element deletion (IED) based finite element analysis (FEA) was developed on femur fracture analysis and compared with two widly-used approaches (XFEM and USDFLD). It was also evaluated using the in-vitro loading test. Moreover, the effects of different impact speeds, fall postures, and cortical thicknesses on fracture types and mechanical responses were investigated. Impact speeds cause different crack propagation behaviors of the femoral neck. Falling forward was less likely to cause proximal femoral fracture compared with falling backward. The model with thin cortical bone was prone to fracture. These provides a theoretical basis and method for predicting femoral fracture risk in the elderly.


Author(s):  
Alden Yellowhorse ◽  
Larry L. Howell

Ensuring that deployable mechanisms are sufficiently rigid is a major challenge due to their large size relative to their mass. This paper examines three basic types of stiffener that can be applied to light, origami-inspired structures to manage their stiffness. These stiffeners are modeled analytically to enable prediction and optimization of their behavior. The results obtained from this analysis are compared to results from a finite-element analysis and experimental data. After verifying these models, the advantages and disadvantages of each stiffener type are considered. This comparison will facilitate stiffener selection for future engineering applications.


2017 ◽  
Vol 103 (1) ◽  
pp. 196-205 ◽  
Author(s):  
Natalie E Cusano ◽  
Mishaela R Rubin ◽  
Barbara C Silva ◽  
Yu-Kwang Donovan Tay ◽  
John M Williams ◽  
...  

Abstract Context High-resolution peripheral quantitative computed tomography (HRpQCT) is a noninvasive imaging technology that can provide insight into skeletal microstructure and strength. In asymptomatic primary hyperparathyroidism (PHPT), HRpQCT imaging has demonstrated both decreased cortical and trabecular indices, consistent with evidence for increased fracture risk. There are limited data regarding changes in HRpQCT parameters postparathyroidectomy. Objective To evaluate changes in skeletal microstructure by HRpQCT in subjects with PHPT after parathyroidectomy. Design We studied 29 subjects with PHPT (21 women, 8 men) with HRpQCT at baseline and 6, 12, 18, and 24 months postparathyroidectomy. Main Outcome Measures Volumetric bone mineral density, microarchitectural indices, and finite element analysis at the distal radius and tibia. Results At both the radius and tibia, there were significant improvements in total, cortical, and trabecular volumetric bone density as early as 6 months postparathyroidectomy (24-month values for total volumetric bone density, radius: +2.8 ± 4%, tibia: +4.4 ± 4%; P < 0.0001 for both), cortical thickness (radius: +1.1 ± 2%, tibia: +2.0 ± 3%; P < 0.01 for both), and trabecular bone volume (radius: +3.8 ± 5%, tibia: +3.2 ± 4%; P < 0.0001 for both). At both sites, by finite element analysis, stiffness and failure load were improved starting at 6 months postparathyroidectomy (24-month values for failure load, radius: +6.2 ± 6%, tibia: +4.8 ± 7%; P < 0.0001 for both). Conclusions These results provide information about skeletal microarchitecture in subjects with PHPT followed through 2 years after parathyroidectomy. Estimated bone strength is improved, consistent with data showing decreased fracture risk postparathyroidectomy.


2019 ◽  
Vol 105 (3) ◽  
pp. 252-262 ◽  
Author(s):  
Leo D. Westbury ◽  
Clare Shere ◽  
Mark H. Edwards ◽  
Cyrus Cooper ◽  
Elaine M. Dennison ◽  
...  

2018 ◽  
Vol 7 (4.13) ◽  
pp. 214-220
Author(s):  
Mohd Nasri Ishak ◽  
Abd Rahim Abu Talib ◽  
Mohammad Yazdi Harmin

Current design of safety syringes requires two handed operation and additional processes which is not similar to the normal syringes. Due to this concern, a new design of safety syringe is introduced in order to produce a safety syringe which allows a single-handed operation and similar to the operation of a normal syringes. This paper presents the material selection process and design analysis of a newly devel-oped multi-purpose disposable safety syringe. Based on the design analysis, the force which needed to dismantle the nozzle is found to be 20 N and this value is practical for the end users. The finite element analysis had also shown that the design concept is safe and has safety feature for the user to use. In addition, copolymer is proven as the best material selection for safety syringe production.


2008 ◽  
Vol 11 (3) ◽  
pp. 467-468 ◽  
Author(s):  
Tony M. Keaveny ◽  
Lynn M. Marshall ◽  
Carrie M. Nielson ◽  
Steven R. Cummings ◽  
Paul F. Hoffmann ◽  
...  

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