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Method and Instrumented Fixture for Femoral Fracture Testing in a Sideways Fall-on-the-Hip Position
Published on: August 17, 2017
Osteoporotic Hip Fracture Prediction: Is T-Score-Based Criterion Enough? A Hip Structural Analysis-Based Model
Alessandra Aldieri1, Mara Terzini2, Giangiacomo Osella3
1PolitoBIOMed Lab,Department of Mechanical andAerospace Engineering,Politecnico di Torino,Corso Duca degli Abruzzi,Turin 24-10129, Italye-mail: alessandra.aldieri@polito.it.
Insights
Hip structural analysis (HSA) variables, including buckling ratio and neck-shaft angle, can improve osteoporosis fracture risk prediction beyond bone mineral density (BMD). This study confirms their suitability for identifying high-risk individuals.
Area of Science:
- Biomedical Engineering
- Orthopedics
- Radiology
Background:
- Current osteoporosis diagnosis relies on bone mineral density (BMD), which has limited accuracy in predicting fracture risk.
- Hip structural analysis (HSA) variables offer geometric insights into the proximal femur, potentially enhancing fracture prediction.
Purpose of the Study:
- To evaluate the effectiveness of HSA parameters as supplementary predictors of hip fracture risk.
- To determine if HSA variables can improve upon BMD-based fracture risk assessment.
Main Methods:
- Creation of 28 patient-specific 3D models of the proximal femur using CT images.
- Simulation of sideways falls using finite element (FE) analysis to calculate a risk factor (RF) based on principal strains.
- Multivariate linear regression analysis to assess the predictive power of HSA variable combinations, optimized using the Akaike information criterion (AIC).
Main Results:
- The optimal regression model identified two key HSA variables: buckling ratio (BR) and neck-shaft angle (NSA).
- Validation on two additional patients who experienced hip fractures confirmed the model's ability to classify them as high-risk.
- The combination of BR and NSA demonstrated significant predictive power for hip fracture risk.
Conclusions:
- HSA parameters, specifically BR and NSA, are valuable additions to fracture risk assessment in osteoporosis.
- These geometric variables enhance the prediction of hip fracture risk beyond traditional BMD measurements.
- The developed FE analysis model shows promise for clinical application in identifying at-risk individuals.
Abstract:
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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