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document
A novel methodology for generating 3D finite element models of the hip from 2D radiographs . Finite element ( FE ) modelling has been proposed as a tool for estimating fracture risk and patient-specific FE models are commonly based on computed tomography ( CT ) . Here , we present a novel method to automatically create personalised 3D models from standard 2D hip radiographs . A set of geometrical parameters of the femur were determined from seven a-p hip radiographs and compared to the 3D femoral shape obtained from CT as training material ; the error in reconstructing the 3D model from the 2D radiographs was assessed . Using the geometry parameters as the input , the 3D shape of another 21 femora was built and meshed , separating a cortical and trabecular compartment . The material properties were derived from the homogeneity index assessed by texture analysis of the radiographs , with focus on the principal tensile and compressive trabecular systems . The ability of these FE models to predict failure load as determined by experimental biomechanical testing was evaluated and compared to the predictive ability of DXA . The average reconstruction error of the 3D models was 1.77 mm ( ±1.17 mm ) , with the error being smallest in the femoral head and neck , and greatest in the trochanter . The correlation of the FE predicted failure load with the experimental failure load was r ( 2 ) =64 % for the reconstruction FE model , which was significantly better ( p < 0.05 ) than that for DXA ( r ( 2 ) =24 % ) . This novel method for automatically constructing a patient-specific 3D finite element model from standard 2D radiographs shows encouraging results in estimating patient-specific failure loads .
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Intervention_Other
3D finite element models
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Intervention_Other
2D radiographs
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Intervention_Other
Finite element ( FE ) modelling
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Intervention_Other
patient-specific FE models
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Intervention_Other
computed tomography
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Intervention_Other
create personalised 3D models from standard 2D hip radiographs
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Intervention_Other
a-p hip radiographs
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Intervention_Other
3D femoral shape obtained from CT
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Intervention_Other
FE models
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Outcome_Physical
fracture risk
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Outcome_Physical
homogeneity index
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Outcome_Physical
failure load
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Outcome_Other
average reconstruction error
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Participant_Condition
models of the hip