Micro-CT based finite element models of cancellous bone predict accurately displacement once the boundary condition is well replicated: A validation study. (January 2017)

• Record Type: Journal Article
• Authors: Chen, Yuan; Dall׳Ara, Enrico; Sales, Erika; Manda, Krishnagoud; Wallace, Robert; Pankaj, Pankaj; Viceconti, Marco
• Is Part Of: Journal of the mechanical behavior of biomedical materials. Volume 65(2017)
• Page Start: 644
• Page End: 651
• Publication Date: 2017-01
• Subjects: MicroCT -- microFE -- Cancellous bone -- DVC -- Validation; Biomedical materials -- Periodicals; Biomedical materials -- Mechanical properties -- Periodicals; Biomedical materials; Biomedical materials -- Mechanical properties; Periodicals; Electronic journals; 610.28
• DOI: 10.1016/j.jmbbm.2016.09.014
• Languages: English
• ISSNs: 1751-6161

Abstract

Abstract: Non-destructive 3D micro-computed tomography (microCT) based finite element (microFE) models are used to estimate bone mechanical properties at tissue level. However, their validation remains challenging. Recent improvements in the quantification of displacements in bone tissue biopsies subjected to staged compression, using refined Digital Volume Correlation (DVC) techniques, now provide a full field displacement information accurate enough to be used for microFE validation. In this study, three specimens (two humans and one bovine) were tested with two different experimental set-ups, and the resulting data processed with the same DVC algorithm. The resulting displacement vector field was compared to that predicted by microFE models solved with three different boundary conditions (BC): nominal force resultant, nominal displacement resultant, distributed displacement. The first two conditions were obtained directly from the measurements provided by the experimental jigs, whereas in the third case the displacement field measured by the DVC in the top and bottom layer of the specimen was applied. Results show excellent relationship between the numerical predictions (x) and the experiments (y) when using BC derived from the DVC measurements (UX : y=1.07x−0.002, RMSE: 0.001 mm; UY : y=1.03x−0.001, RMSE: 0.001 mm; UZ : y=x+0.0002, RMSE: 0.001 mm for bovine specimen), whereas only poor correlation was found using BCs according to experiment set-ups. In conclusion, microFE models were found to predict accurately the vectorial displacement field using interpolated displacement boundary condition from DVC measurement.