Sensitivity of Modeling Parameters in Proximal Femur Analyses

2000 ◽  
Author(s):  
Eric L. Wang ◽  
Yanyao Jiang ◽  
Lixia Fan ◽  
Brian Greer
Keyword(s):  
Hip Fracture ◽  
Proximal Femur ◽  
Material Properties ◽  
Applied Load ◽  
Loading Rate ◽  
Frictional Resistance ◽  
Fracture Load ◽  
Loading Direction ◽  
Structural Capacity ◽  
Femoral Geometry

Abstract Hip fracture risk can be quantified using a factor of risk (Hayes et al., 1996): (1) Φ = Applied load / Fracture load The structural capacity, the denominator, can be affected by many parameters including femoral geometry, material properties, load locations, loading direction, loading rate, and frictional resistance.

scholarly journals Early mortality in hip fracture patients admitted during first wave of the COVID-19 pandemic in Northern Italy: a multicentre study

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Dante Dallari ◽  
Luigi Zagra ◽  
Pietro Cimatti ◽  
Nicola Guindani ◽  
Rocco D’Apolito ◽  
...  
Keyword(s):  
Hip Fracture ◽  
Mortality Rate ◽  
Multicentre Study ◽  
Proximal Femur ◽  
Femur Fracture ◽  
Northern Italy ◽  
Proximal Femur Fracture ◽  
Time To Surgery ◽  
Fracture Management ◽  
The Mean

Abstract Background Treatment of hip fractures during the coronavirus disease 2019 (COVID-19) pandemic has posed unique challenges for the management of COVID-19-infected patients and the maintenance of standards of care. The primary endpoint of this study is to compare the mortality rate at 1 month after surgery in symptomatic COVID-positive patients with that of asymptomatic patients. A secondary endpoint of the study is to evaluate, in the two groups of patients, mortality at 1 month on the basis of type of fracture and type of surgical treatment. Materials and methods For this retrospective multicentre study, we reviewed the medical records of patients hospitalised for proximal femur fracture at 14 hospitals in Northern Italy. Two groups were formed: COVID-19-positive patients (C+ group) presented symptoms, had a positive swab for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and received treatment for COVID-19; COVID-19-negative patients (C− group) were asymptomatic and tested negative for SARS-CoV-2. The two groups were compared for differences in time to surgery, survival rate and complications rate. The follow-up period was 1 month. Results Of the 1390 patients admitted for acute care for any reason, 477 had a proximal femur fracture; 53 were C+ but only 12/53 were diagnosed as such at admission. The mean age was > 80 years, and the mean American Society of Anesthesiologists (ASA) score was 3 in both groups. There was no substantial difference in time to surgery (on average, 2.3 days for the C+ group and 2.8 for the C− group). As expected, a higher mortality rate was recorded for the C+ group but not associated with the type of hip fracture or treatment. No correlation was found between early treatment (< 48 h to surgery) and better outcome in the C+ group. Conclusions Hip fracture in COVID-19-positive patients accounted for 11% of the total. On average, the time to surgery was > 48 h, which reflects the difficulty of maintaining normal workflow during a medical emergency such as the present pandemic and notwithstanding the suspension of non-urgent procedures. Hip fracture was associated with a higher 30-day mortality rate in COVID-19-positive patients than in COVID-19-negative patients. This fact should be considered when communicating with patients and/or their family. Our data suggest no substantial difference in hip fracture management between patients with or without COVID-19 infection. In this sample, the COVID-19-positive patients were generally asymptomatic at admission; therefore, routine screening is recommended. Level of evidence Therapeutic study, level 4.

scholarly journals Development of friction-induced triboluminescent sensor for load monitoring

2017 ◽  
Vol 29 (5) ◽  
pp. 883-895 ◽  
Author(s):  
Md Abu S Shohag ◽  
Zhengqian Jiang ◽  
Emily C Hammel ◽  
Lucas Braga Carani ◽  
David O Olawale ◽  
...  
Keyword(s):  
Applied Load ◽  
Loading Rate ◽  
Turbine Blades ◽  
Wind Turbine Blades ◽  
Loading Rates ◽  
Load Monitoring ◽  
The Coefficient Of Friction ◽  
Dynamic Structures ◽  
Sample Configuration

Real-time load monitoring of critical civil and mechanical structures especially dynamic structures such as wind turbine blades is imperative for longer service life. This article proposed a novel sensor system based on the proprietary in situ triboluminescent optical fiber (ITOF) sensor for dynamic load monitoring. The new ITOF sensor patch consists of an ITOF sensor network with micro-exciters integrated within a polymer matrix. The sensor patch was subjected to repeated flexural loading and produced triboluminescent emissions due to the friction between micro-exciters and ITOF sensors corresponding to each loading cycle. The friction-induced triboluminescent intensity directly depends on the loading rate, the coefficient of friction, and the applied load on patch. In general, the triboluminescent intensity increases exponentially with an increase in load. Additionally, the sensor patches comprising the coarser micro-exciters exhibited better results. Similarly, better results were achieved at higher loading rates although a threshold loading rate is required to excite the triboluminescent crystals for this sample configuration. The proposed new sensor has the ability to monitor dynamic continuous applied loads.

Trabecular Surface Remodeling Simulation for Cancellous Bone Using Microstructural Voxel Finite Element Models

2001 ◽  
Vol 123 (5) ◽  
pp. 403-409 ◽  
Author(s):  
Taiji Adachi ◽  
Ken-ichi Tsubota ◽  
Yoshihiro Tomita ◽  
Scott J. Hollister
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Cancellous Bone ◽  
Applied Load ◽  
Morphological Changes ◽  
Finite Element Models ◽  
Structural Level ◽  
Loading Direction ◽  
Surface Remodeling ◽  
Trabecular Surface

A computational simulation method for three-dimensional trabecular surface remodeling was proposed, using voxel finite element models of cancellous bone, and was applied to the experimental data. In the simulation, the trabecular microstructure was modeled based on digital images, and its morphological changes due to surface movement at the trabecular level were directly expressed by removing/adding the voxel elements from/to the trabecular surface. A remodeling simulation at the single trabecular level under uniaxial compressive loading demonstrated smooth morphological changes even though the trabeculae were modeled with discrete voxel elements. Moreover, the trabecular axis rotated toward the loading direction with increasing stiffness, simulating functional adaptation to the applied load. In the remodeling simulation at the trabecular structural level, a cancellous bone cube was modeled using a digital image obtained by microcomputed tomography (μCT), and was uniaxially compressed. As a result, the apparent stiffness against the applied load increased by remodeling, in which the trabeculae reoriented to the loading direction. In addition, changes in the structural indices of the trabecular architecture coincided qualitatively with previously published experimental observations. Through these studies, it was demonstrated that the newly proposed voxel simulation technique enables us to simulate the trabecular surface remodeling and to compare the results obtained using this technique with the in vivo experimental data in the investigation of the adaptive bone remodeling phenomenon.

Effect of Loading Direction and Bone Density Distribution in Assessing Hip Fracture via Finite Element Analysis

2020 ◽  
Author(s):  
Rabina Awal ◽  
Tanvir R. Faisal
Keyword(s):  
Hip Fracture ◽  
Bone Density ◽  
Fracture Risk ◽  
Risk Index ◽  
Transverse Plane ◽  
Coronal Plane ◽  
Mineral Density ◽  
Femoral Neck Axis ◽  
Loading Direction ◽  
The Impact

Abstract An accurate assessment of hip fracture risk requires a proper consideration of parameters affecting the fracture. In general, hip fracture is affected by bone morphology, bone mineral Density (BMD), and load amount. Hip fracture is an outcome of the interaction of all those parameters including loading directions. Assessing the effect of the parameters individually may not correctly reflect the root cause of the hip fracture. Hence, this research aims at analyzing the significance of parameters and their interaction. A multivariate regression model was used considering bone density (ρash), different loading directions during sideways fall, represented by load angle (α) on the coronal plane and angle (β) on the transverse plane as independent parameters and Fracture Risk Index (FRI) as a dependent parameter. The statistical results showing the significant value of 0.7321 for α, and 0.0001 for β and ρash indicates that the effect of loading direction about femoral shaft on the coronal plane (α) does not have impact on fracture risk while loading direction about femoral neck axis on the transverse plane (β) and ρash have the significant impact. Furthermore, the analysis of the interaction of parameters shows that the impact of β on fracture risk may depends more on bone density as the significance of interaction of β and ρash is 0.0001.

scholarly journals The effect of loading direction on the fracture behaviors of cortical bone at a dynamic loading rate

2020 ◽  
Vol 142 ◽  
pp. 104015 ◽  
Author(s):  
Xuedong Zhai ◽  
Yizhou Nie ◽  
Jinling Gao ◽  
Nesredin Kedir ◽  
Ben Claus ◽  
...  
Keyword(s):  
Cortical Bone ◽  
Dynamic Loading ◽  
Loading Rate ◽  
Loading Direction ◽  
Fracture Behaviors

87 Prediction of Hip Fracture Load from Radiographs by Combined Analysis of Trabecular Bone Structure and Bone Geometry

2009 ◽  
Vol 12 (1) ◽  
pp. 125
Author(s):  
P. Pulkkinen ◽  
T. Jämsä ◽  
E.-M. Lochmüller ◽  
V. Kuhn ◽  
M. Nieminen ◽  
...  
Keyword(s):  
Hip Fracture ◽  
Trabecular Bone ◽  
Bone Structure ◽  
Bone Geometry ◽  
Fracture Load ◽  
Trabecular Bone Structure ◽  
Combined Analysis
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