Validation of an anatomy specific finite element model of Colles' fracture

Osteoporotic fractures are harmful injuries and their number is on the rise. Distal radius fractures are precursors of other osteoporotic fractures. The wrist's bony geometry and trabecular architecture can be assessed in vivo using the recently introduced HR-pQCT. The goal of this study was the validation of a newly developed HR-pQCT based anatomy specific FE technique including separation of cortical and trabecular bone regions using an experimental model for producing Colles' fractures. Mechanical compression tests of 21 embalmed human radii were conducted. Continuum level FE models were built using HR-pQCT images of the bones and nonlinear analyses were performed using boundary conditions highly similar to the mechanical tests. Density and fabric based material properties were taken from previous tests on biopsies and no adjustments were made. Numerical results provided good prediction of the experimental stiffness (R² = 0.793) and even better for strength (R² = 0.874). High damage zones of the FE models coincided with the actual failure patterns of the specimens. These encouraging results allow to conclude that the developed method represents an attractive and efficient tool for simulation of Colles' fracture.