Discrimination of Cervical and Trochanteric Hip Fractures UsingRadiography-Based Two-Dimensional Finite Element Models

摘要

Introduction: Predictors of fracture risk differ between cervical and trochanteric hip fractures. The aim of thisexperimental study was therefore to investigate whether two-dimensional (2D) finite element (FE) models, generated fromstandard radiographs, are able to predict and discriminate fracture types, originating from a simulated fall on the greatertrochanter. Methods: A semi-automatic custom algorithm was applied to segment cortical and trabecular bone contoursfrom radiographs of 49 female cadaver femora (mean age 80.7±10.3 years). Two types of 2D FE models were generated,either one or four material properties assigned to the trabecular bone. The cartilage and soft tissue were also simulated,and the boundary conditions were mimicking the experiment. VonMises stress distributions within the trabecular bonewere evaluated and the regions of maximum continuous stress patterns were determined. Results: The best fracture typeprediction was obtained with the criterion that a cervical fracture was predicted if the maximum stress in trabecular bonewas located at the superior part of the femoral neck and the maximum continuous stress pattern through the neck region;and in all other cases a trochanteric fracture was predicted. The two different models predicted 79.6% and 85.7% of thefracture cases correctly, in comparison with the actual failure type. Conclusion: Our results suggest that the cervical andtrochanteric hip fractures can be discriminated with a satisfactory level of accuracy, using a relatively simple radiographybased2D model. Based on the current experimental findings, the predictive power of these models should now be testedin clinical studies.