How accurately can we predict the fracture load of the proximal femur using finite element models?
BACKGROUND
Current clinical methods for fracture prediction rely on two-dimensional imaging methods such as dual-energy X-ray absorptiometry and have limited predictive value. Several researchers have tried to integrate three-dimensional imaging techniques with the finite element (FE) method to improve the accuracy of fracture predictions. Before FE models could be used in clinical settings, a thorough validation of their accuracy is required. In this paper, we try to evaluate the current state of accuracy of subject-specific FE models that are used for prediction of the fracture load of proximal femora.


METHODS
All the studies that have used FE for prediction of fracture load and have compared the predicted fracture load with experimentally measured fracture loads in vitro are identified through a systematic search of the literature. A quantitative analysis of the results of those studies has been carried out to determine the absolute prediction error, percentage error, and linear correlations between predicted and measured fracture loads.


RESULTS
The reported coefficients of determination (R(2)) vary between 0.773 and 0.96 while the percentage error in prediction of fracture load varies between 5 and 46% with most studies reporting percentage errors between 10 and 20%.


CONCLUSIONS
We conclude that FE models, which are currently used only experimentally, are in general more accurate than clinically used fracture risk assessment techniques. However, the accuracy of FE models depends on the details of their modeling methodologies. Therefore, modeling procedures need to be optimized and standardized before FE could be used in clinical settings.
Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands.
Sven
S
van den Munckhof
Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, Delft 2628 CD, The Netherlands. Electronic address: a.a.zadpoor@tudelft.nl.
Amir Abbas
AA
Zadpoor
D015502:Absorptiometry, Photon; D005264:Femoral Fractures / Q000175:diagnosis / Q000503:physiopathology*; D005269:Femur / Q000502:physiology*; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D008954:Models, Biological; D058866:Osteoporotic Fractures / Q000503:physiopathology*; D011237:Predictive Value of Tests; D016474:Weight-Bearing / Q000502:physiology*
Accuracy assessment; Femoral fracture; Finite element method; Osteoporosis; Patient-specific model; Review