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

Author(s):  
Rabina Awal ◽  
Tanvir R. Faisal

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.

Author(s):  
Rabina Awal ◽  
Tanvir Faisal

Abstract An accurate assessment of hip fracture risk requires a proper consideration of parameters affecting the fracture. In general, hip fracture is assessed based on Bone Mineral Density (BMD) and load amount, but hip fracture is an outcome of the interaction of the parameters such as loading directions, bone density, which are often disregarded. 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 in assessing the fracture risk. A multiple regression analysis has been conducted considering bone density (\rho_ash), different loading directions during sideways fall, represented by load angle (\alpha) about femoral shaft on the coronal plane and angle (\beta) about femoral neck axis 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 , and 0.0001 for and ?_ash indicate that the effect of loading direction (\alpha) does not have impact on fracture risk in comparison with the loading direction (\beta) and (\rho_ash). Furthermore, the analysis of the interaction of parameters shows that the impact of \beta on fracture risk may depends more on bone density.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1105.1-1106
Author(s):  
S. Garcia ◽  
B. M. Fernandes ◽  
S. Ganhão ◽  
M. Rato ◽  
F. Pinheiro ◽  
...  

Background:Although poorly understood, patients with Systemic Sclerosis (SSc) seem to have higher prevalence of low bone mineral density (BMD) and an increased spine fracture risk.Objectives:We aim to determine, by conventional densitometry (DXA) and using the fracture risk assessment tool (FRAX), the prevalence of low BMD and the fracture risk, respectively, in our SSc cohort and its potential determinants.Methods:Observational transversal study was performed including consecutive patients with the diagnosis of SSc. We collected data regarding demographics, BMD (lumbar spine and femoral neck) and occurrence of fracture. Ten-year risk of osteoporotic fracture was estimated using FRAXv4.1with the Portuguese population reference. Statistical analysis was performed using SPSS 23.0; p<0.01 was considered statistically significant.Results:Median age of patients (n=97) was 62 years old [56, 70], 88.7% females (n=86). Seventy-eight patients (80.4%) had limited cutaneous form, 5 (5.2%) presented a diffuse cutaneous form and 13 (13.4%) an overlap syndrome. Regarding clinical features: digital ulcers in 30 patients (30.9%), interstitial lung disease (ILD) in 16 (6.5%), gastrointestinal involvement in 16 (16.5%), miositis in 4 (4.1%) and pulmonary arterial hypertension in 3 (3.1%). Anti-topoisomerase I antibody (anti-Scl70) positivity was present in 15 patients (15.5%) and anti-centromere antibody (ACA) positivity in 63 (64.9%). Nine patients (9.3%) were smokers and 6 (6.2%) reported an alcohol consumption of 3 or more units/day. Median body mass index (BMI) was 25.4 Kg/m2[21.4, 29.1], with 5 patients (5.2%) being underweight. Vitamin D insufficiency was reported in 19 patients (19.6%). Twenty-one patients (21.6%) have been exposed to oral glucocorticoids (GCT) for more than 3 months at a dose of 5mg daily or more. Eleven patients (11.3%) had previous low impact fractures: 10 of which were vertebral and 1 wrist fracture. Regarding the prescribed anti-osteoporotic treatment (AOP), we found: alendronate (n=7, 7.2%), zoledronic acid (n=7, 7.2%), denosumab (n=2, 2.1%) and teriparatide (n=1, 1%).Low BMD was present in 45 patients (46.4%); median femoral neck BMD (FN-BMD) was 0.827 [0.709, 0.893].Ten year probability of fracture (%) was: median risk for major fracture was 5.1 [3.5, 9.7] and 3.8 [2.5, 8], with and without FN-BMD, respectively; for hip fracture the estimated risk was 1.2 [0.6, 3.1] and 1.0 [0.4, 2.5], with and without FN-BMD, respectively. According to FRAX thresholds for the Portuguese population, 25 patients (25.8%) met criteria to start AOP treatment. Among them, only 10 patients (40%) started it, as the agreement between the indication to treat by FRAX and the onset of treatment was weak (k= 0.338). A strong agreement was found between FRAX risk threshold with DXA and World Health Organization (WHO) threshold for starting AOP (k= 0.814) and no agreement was found between FRAX risk without DXA and WHO threshold.FN-BMD presented a weak correlation with BMI (r = 0.393), a moderate inverse correlation with major fracture risk with and without FN-BMD (r = -0.704, r=-0.412, respectively) and with hip fracture risk with and without FN-BMD (r = -0.799, r=-0.412, respectively). Major fracture risk with and without FN-BMD presented a moderate correlation with spine fractures (r = 0.350; r=0.397, respectively).No correlation was found between WHO threshold and spine fractures. No correlations were found between FN-BMD or fracture risk estimated by FRAX and disease manifestations, anti-Scl70 or ACA positivity, vitamin D insufficiency, smoking or GCT use.Conclusion:In our cohort, low BMD was prevalent and had correlation with BMI. FRAX appears to be an useful instrument as it correlated with spine fractures, contrary to what was verified when we used the WHO threshold. Early monitoring of BMD and estimating fracture risk using FRAX appear to be useful tools for the prevention of fractures in this population.Disclosure of Interests:Salomé Garcia: None declared, Bruno Miguel Fernandes: None declared, Sara Ganhão: None declared, Maria Rato: None declared, Filipe Pinheiro: None declared, Georgina Terroso: None declared, Miguel Bernardes Speakers bureau: Abbvie, Amgen, Biogen, Eli-Lilly, Glaxo-Smith-Kline, Pfizer, Janssen, Novartis, Lúcia Costa: None declared


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 &lt; 0.0001 for both), cortical thickness (radius: +1.1 ± 2%, tibia: +2.0 ± 3%; P &lt; 0.01 for both), and trabecular bone volume (radius: +3.8 ± 5%, tibia: +3.2 ± 4%; P &lt; 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 &lt; 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.


2020 ◽  
Author(s):  
Chan Ho Park ◽  
Jun-Il Yoo ◽  
Chang Hyun Choi ◽  
You-Sung Suh

Abstract Background: Switching the prescription from bone-forming medication to resorptive agents is reportedly effective for patients with severe osteoporosis. The objective of this study is to determine the impact of implementing short-term teriparatide (TPTD) intervention before denosumab (DMab) therapy compared with DMab therapy alone for 1 year after hip fracture.Methods: TPTD was administered to 24 patients for an average of 12.1 weeks after which the intervention was switched to DMab therapy for 12 months (group 1). DMab alone was administered to 16 patients for 12 months (group 2). Bone mineral density (BMD) was evaluated before and after treatment at the 1-year follow-up. The improvement of BMD and T-score in hip and spine was compared with the levels of bone turnover marker.Results: The difference of hip BMD after osteoporosis treatment was -0.0081±0.03 in group 1 and 0.0074±0.04 in group 2 (p=0.180). The difference of spine BMD was 0.0819±0.04 in group 1 and 0.0145±0.03 in group 2 (p<0.001). BMD and T-score of the spine improved significantly in groups 1 and 2 (p < 0.001). There was no statistical difference in C-terminal telopeptide and osteocalcin level. Conclusion: Short-term TPTD administration followed by DMab alone was effective only in improving spine BMD. Short-term treatment with TPTD caused mild improvement in femur neck BMD compared with DMab alone. However, further research with a longer duration of TPTD treatment is warranted, as our findings lack statistical significance.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Zewei Shen ◽  
◽  
Canqing Yu ◽  
Yu Guo ◽  
Zheng Bian ◽  
...  

Abstract Summary In a Chinese population from both urban and rural areas, weight loss of ≥ 5 kg from early adulthood to midlife was associated with a higher risk of hip fracture and lower BMD in later life. Introduction This study investigates the association of the long-term weight loss from young adulthood through the middle ages with the subsequent 10-year risk of hospitalized fracture and calcaneus bone mineral density (BMD). Methods China Kadoorie Biobank (CKB) was established during 2004–2008 in ten areas across China. Weight at age 25 years was self-reported at baseline, and weight at baseline and resurvey was measured by the calibrated equipment. Outcomes were hospitalized fracture during follow-up and calcaneus BMD measured at resurvey. Analysis for fracture risk included 411,812 participants who were free of fracture in the last 5 years before baseline, cancer, or stroke at any time before baseline. Analysis for BMD included 21,453 participants who participated in the resurvey of 2013–2014 with the same exclusion criteria as above. Results The mean age was 50.8 at baseline and 58.4 at resurvey. Median weight change from age 25 to baseline was 4.4 kg, with 20.7% losing weight and 58.5% gaining weight. During a median follow-up of 10.1 years, we documented 13,065 cases of first diagnosed fracture hospitalizations, including 1222 hip fracture. Compared with participants whose weight was stable (± 2.4 kg), the adjusted hazard ratios (95% CIs) for those with weight loss of ≥ 5.0 kg from age 25 to baseline was 1.39 (1.17 to 1.66) for hip fracture. Weight loss was not associated with fracture risk at other sites. Those with weight loss from age 25 to resurvey had the lowest BMD measures, with β (95% CIs) of − 4.52 (− 5.08 to − 3.96) for broadband ultrasound attenuation (BUA), − 4.83 (− 6.98, − 2.67) for speed of sound (SOS), and − 4.36 (− 5.22, − 3.49) for stiffness index (SI). Conclusions Weight loss from early adulthood to midlife was associated with a higher risk of hip fracture and lower BMD in later life.


2020 ◽  
Vol 21 (18) ◽  
pp. 6670
Author(s):  
Jordan Marcano Anaya ◽  
Wendy B. Bollag ◽  
Mark W. Hamrick ◽  
Carlos M. Isales

Although aging is considered a normal process, there are cellular and molecular changes that occur with aging that may be detrimental to health. Osteoporosis is one of the most common age-related degenerative diseases, and its progression correlates with aging and decreased capacity for stem cell differentiation and proliferation in both men and women. Tryptophan metabolism through the kynurenine pathway appears to be a key factor in promoting bone-aging phenotypes, promoting bone breakdown and interfering with stem cell function and osteogenesis; however, little data is available on the impact of tryptophan metabolites downstream of kynurenine. Here we review available data on the impact of these tryptophan breakdown products on the body in general and, when available, the existing evidence of their impact on bone. A number of tryptophan metabolites (e.g., 3-hydroxykynurenine (3HKYN), kynurenic acid (KYNA) and anthranilic acid (AA)) have a detrimental effect on bone, decreasing bone mineral density (BMD) and increasing fracture risk. Other metabolites (e.g., 3-hydroxyAA, xanthurenic acid (XA), picolinic acid (PIA), quinolinic acid (QA), and NAD+) promote an increase in bone mineral density and are associated with lower fracture risk. Furthermore, the effects of other tryptophan breakdown products (e.g., serotonin) are complex, with either anabolic or catabolic actions on bone depending on their source. The mechanisms involved in the cellular actions of these tryptophan metabolites on bone are not yet fully known and will require further research as they are potential therapeutic targets. The current review is meant as a brief overview of existing English language literature on tryptophan and its metabolites and their effects on stem cells and musculoskeletal systems. The search terms used for a Medline database search were: kynurenine, mesenchymal stem cells, bone loss, tryptophan metabolism, aging, and oxidative stress.


2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Alessandra Aldieri ◽  
Mara Terzini ◽  
Giangiacomo Osella ◽  
Adriano M. Priola ◽  
Alberto Angeli ◽  
...  

At present, the current gold-standard for osteoporosis diagnosis is based on bone mineral density (BMD) measurement, which, however, has been demonstrated to poorly estimate fracture risk. Further parameters in the hands of the clinicians are represented by the hip structural analysis (HSA) variables, which include geometric information of the proximal femur cross section. The purpose of this study was to investigate the suitability of HSA parameters as additional hip fracture risk predictors. With this aim, twenty-eight three-dimensional patient-specific models of the proximal femur were built from computed tomography (CT) images and a sideways fall condition was reproduced by finite element (FE) analyses. A tensile or compressive predominance based on minimum and maximum principal strains was determined at each volume element and a risk factor (RF) was calculated. The power of HSA variables combinations to predict the maximum superficial RF values was assessed by multivariate linear regression analysis. The optimal regression model, identified through the Akaike information criterion (AIC), only comprises two variables: the buckling ratio (BR) and the neck-shaft angle (NSA). In order to validate the study, the model was tested on two additional patients who suffered a hip fracture after a fall. The results classified the patients in the high risk level, confirming the prediction power of the adopted model.


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