Forecasting Postflight Hip Fracture Probability Using Probabilistic Modeling

2018 ◽  
Vol 141 (1) ◽  
Author(s):  
Beth E. Lewandowski ◽  
Jerry G. Myers

A probabilistic model predicts hip fracture probability for postflight male astronauts during lateral fall scenarios from various heights. A biomechanical representation of the hip provides impact load. Correlations relate spaceflight bone mineral density (BMD) loss and postflight BMD recovery to bone strength (BS). Translations convert fracture risk index (FRI), the ratio of applied load (AL) to BS, to fracture probability. Parameter distributions capture uncertainty and Monte Carlo simulations provide probability outcomes. The fracture probability for a 1 m fall 0 days postflight is 15% greater than preflight and remains 6% greater than pre-flight at 365 days postflight. Probability quantification provides insight into how spaceflight induced BMD loss affects fracture probability. A bone loss rate reflecting improved exercise countermeasures and dietary intake further reduces the postflight fracture probability to 6% greater than preflight at 0 days postflight and 2% greater at 365 days postflight. Quantification informs assessments of countermeasure effectiveness. When preflight BMD is one standard deviation below mean astronaut preflight BMD, fracture probability at 0 days postflight is 34% greater than the preflight fracture probability calculated with mean BMD and 28% greater at 365 days postflight. Quantification aids review of astronaut BMD fitness for duty standards. Increases in postflight fracture probability are associated with an estimated 18% reduction in postflight BS. Therefore, a 0.82 deconditioning coefficient modifies force application limits for crew vehicles.

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.


2005 ◽  
Vol 17 (1) ◽  
pp. 54-60 ◽  
Author(s):  
Yunbo Duan ◽  
François Duboeuf ◽  
Françoise Munoz ◽  
Pierre D. Delmas ◽  
Ego Seeman

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 833.2-834
Author(s):  
S. Garcia ◽  
B. M. Fernandes ◽  
M. Rato ◽  
F. Oliveira Pinheiro ◽  
D. Fonseca ◽  
...  

Background:Teriparatide has been shown to increase spine and hip bone mineral density (BMD) and to reduce vertebral and non-vertebral fractures. (1) It is currently not clear whether the effect of teriparatide is dependent on the baseline risk of fracture or osteoporosis (OP) type, a finding that could have an impact on our therapeutic decision.Objectives:Investigate if there is a relationship between teriparatide effect in BMD and baseline 10-year fracture probability, assessed using FRAX®, in primary and secondary OP patients.Methods:This is a longitudinal, retrospective study including consecutive patients with the diagnosis of OP treated with teriparatide for 24 months, with a ten-year follow-up period, at our rheumatology department. Demographic, clinical, laboratorial, BMD and occurrence of fracture data were collected. The 10-year risk of osteoporotic fracture was estimated using the fracture risk assessment tool (FRAX) v 4.1 with the Portuguese population reference. Statistical analysis was performed using the software SPSS 23.0. Correlations between continuous variables were evaluated with spearman coefficient. p<0.05 was considered statistically significant.Results:Eighty patients (88.8% female, median age 65.00 (59; 75)) were included. Forty-nine patients (61.3%) has secondary OP, mainly of cortisonic etiology (61.2%, n=30). Before treatment, median lumbar spine BMD was 0.870 [0.767, 0.964] g/cm2, median T-score of -2.60 (-3.30, -1.90); median total femur BMD was 0.742 [0.667, 0.863] g/cm2, median T-score of -2.10 (-2.80, -1.30); median femoral neck BMD was 0.671 [0.611, 0.787] g/cm2, median T-score of -2.50 [-3.20, -1.85]. Regarding fracture risk, median FRAX-based 10-year major fracture risk (with BMD) at baseline was 16% [10.0; 23], and median hip fracture risk was 7.2% [3.4; 13.8].The median variation of BMD, after finishing teriparatide treatment, in the spine was 0.107 [0.029; 0.228]; median BMD variation in total femur was 0.013 [-0.013; 0.068] and median BMD femoral neck was 0.046 [-0.002; 0.109]. We observed a numerically superior effect, albeit without any statistical significance, of teriparatide on bone mineral density gain in secondary OP (versus primary OP) at lumbar spine, total femur and femoral neck.Most patients continued anti-osteoporotic treatment with a bisphosphonate (81.2%, n=65) and, during follow-up, 17 patients had an incident fracture (8 hip fractures and 6 vertebral fractures), median of 5 [1.75, 8.25] years after ending teriparatide.We found a discrete correlation between FRAX-based hip fracture probability and the variation of bone mineral density in total femur (Spearman’s coefficient 0.248, p = 0.04). There was no correlation between FRAX-based major fracture probability and and the variation of bone mineral density in the spine or femur. When we separately analyze the relationship between the variation in total hip BMD and the FRAX-based fracture risk, depending on whether it is a secondary or primary OP, we find that the correlation is stronger and only remains in secondary OP (Spearman’s coefficient 0.348, p = 0.03).Conclusion:Our data suggest that teriparatide could be an important weapon in the treatment of secondary cause OP, particularly cortisonic, and in patients at high fracture risk, although further larger studies are needed to confirm these findings.References:[1]Kendler DL, Marin F, Zerbini CAF, Russo LA, Greenspan SL, Zikan V, Bagur A, Malouf-Sierra J, Lakatos P, Fahrleitner-Pammer A, Lespessailles E, Minisola S, Body JJ, Geusens P, Möricke R, López-Romero P. Effects of teriparatide and risedronate on new fractures in post-menopausal women with severe osteoporosis (VERO): a multicentre, double-blind, double-dummy, randomised controlled trial. Lancet. 2018 Jan 20;391(10117):230-240. doi: 10.1016/S0140-6736(17)32137-2.Disclosure of Interests:None declared.


2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Hossein Kheirollahi ◽  
Yunhua Luo

Accurate assessment of hip fracture risk is very important to prevent hip fracture and to monitor the effect of a treatment. A subject-specific QCT-based finite element model was constructed to assess hip fracture risk at the critical locations of femur during the single-leg stance and the sideways fall. The aim of this study was to improve the prediction of hip fracture risk by introducing a novel failure criterion to more accurately describe bone failure mechanism. Hip fracture risk index was defined using cross-section strain energy, which is able to integrate information of stresses, strains, and material properties affecting bone failure. It was found that the femoral neck and the intertrochanteric region have higher fracture risk than other parts of the femur, probably owing to the larger content of cancellous bone in these regions. The study results also suggested that women are more prone to hip fracture than men. The findings in this study have a good agreement with those clinical observations reported in the literature. The proposed hip fracture risk index based on strain energy has the potential of more accurate assessment of hip fracture risk. However, experimental validation should be conducted before its clinical applications.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 975.1-975
Author(s):  
H. Azzouzi ◽  
O. Lamkhanat ◽  
I. Linda

Background:Rheumatoid Arthritis (RA) is one of the risk factors for the calculation of the 10 years fracture probability assessed by the FRAX tool.Objectives:The aim was to study the association of disease activity and the 10 year fracture risk probability by the FRAX tool in our RA patients and their impact on fracture prevalence.Methods:Cross-sectional study of the association FRAX and disease activity score (DAS 28 CRP) was designed. Patients with RA were included. Mean DAS was calculated for each patient adjusted on his follow-up duration. Data about patients (demographic, disease characteristics and fracture assessment) were collected. The 10 year fracture risk probability for major osteoporotic fracture was calculated with and without BMD (bone mineral density) using the FRAX tool for Morocco. Descriptive analysis and regressions were performed with SPSS.20. p<0.05 was considered significant.Results:One hundred and ninety nine RA patients were included with mean age of 55.5±12 years. Women represented 91% and 40.1% had osteoporosis. Remission was observed in 86.4% with 95.5% taking methotrexate. 17.1% had vertebral fractures. FRAX and DAS were associated (p=0.03), and both explained vertebral fracture (VF) prevalence. When adjusted on disease parameters, FRAX with and without BMD explained the vertebral prevalence (p=0.02, OR=1.09[1.01-1.19]). However, age remains the only predictor of VF when adjusted on osteoporosis factors (DAS28CRP, menopause, BMI, smoking, diabetes, gender, steroid use, HAQ) and FRAX BMD.Conclusion:Persistent disease activity was associated to high 10 year fracture risk probability calculated by the FRAX tool in RA.Disclosure of Interests:None declared


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


1996 ◽  
Vol 6 (S1) ◽  
pp. 127-127 ◽  
Author(s):  
E. Waern ◽  
C. Christiansen ◽  
I. Gause-Nilsson ◽  
G. Lindstedt ◽  
A. Odén ◽  
...  

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