Material Mapping of QCT-Derived Scapular Models: A Comparison with Micro-CT Loaded Specimens Using Digital Volume Correlation

  • Nikolas K. KnowlesEmail author
  • Jonathan Kusins
  • Mohammadreza Faieghi
  • Melissa Ryan
  • Enrico Dall’Ara
  • Louis M. Ferreira


Subject- and site-specific modeling techniques greatly improve finite element models (FEMs) derived from clinical-resolution CT data. A variety of density-modulus relationships are used in scapula FEMs, but the sensitivity to selection of relationships has yet to be experimentally evaluated. The objectives of this study were to compare quantitative-CT (QCT) derived FEMs mapped with different density-modulus relationships and material mapping strategies to experimentally loaded cadaveric scapular specimens. Six specimens were loaded within a micro-CT (33.5 μm isotropic voxels) using a custom-hexapod loading device. Digital volume correlation (DVC) was used to estimate full-field displacements by registering images in pre- and post-loaded states. Experimental loads were measured using a 6-DOF load cell. QCT-FEMs replicated the experimental setup using DVC-driven boundary conditions (BCs) and were mapped with one of fifteen density-modulus relationships using elemental or nodal material mapping strategies. Models were compared based on predicted QCT-FEM nodal reaction forces compared to experimental load cell measurements and linear regression of the full-field nodal displacements compared to the DVC full-field displacements. Comparing full-field displacements, linear regression showed slopes ranging from 0.86 to 1.06, r-squared values of 0.82–1.00, and max errors of 0.039 mm for all three Cartesian directions. Nearly identical linear regression results occurred for both elemental and nodal material mapping strategies. Comparing QCT-FEM to experimental reaction forces, errors ranged from − 46 to 965% for all specimens, with specimen-specific errors as low as 3%. This study utilized volumetric imaging combined with mechanical loading to derive full-field experimental measurements to evaluate various density-modulus relationships required for QCT-FEMs applied to whole-bone scapular loading. The results suggest that elemental and nodal material mapping strategies are both able to simultaneously replicate experimental full-field displacements and reactions forces dependent on the density-modulus relationship used.


Finite element modeling Material mapping strategies Experimental loading Bone mechanics 



Enrico Dall’Ara and Melissa Ryan were supported by the Engineering and Physical Sciences Research Council (Grant Number: EP/P015778/1).

Supplementary material

10439_2019_2312_MOESM1_ESM.pdf (190 kb)
Supplementary material 1 (PDF 189 kb)


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Copyright information

© Biomedical Engineering Society 2019

Authors and Affiliations

  1. 1.School of Biomedical EngineeringThe University of Western OntarioLondonCanada
  2. 2.Department of Mechanical and Materials EngineeringThe University of Western OntarioLondonCanada
  3. 3.Roth|McFarlane Hand and Upper Limb Centre, St. Josephs Health CareLondonCanada
  4. 4.Collaborative Training Program in MSK Health Research, and Bone and Joint InstituteThe University of Western OntarioLondonCanada
  5. 5.Department of Oncology and Metabolism and INSIGNEO Institute for In Silico MedicineUniversity of SheffieldSheffieldUK
  6. 6.Roth|McFarlane Hand and Upper Limb Centre, Surgical Mechatronics Laboratory, St. Josephs Health CareLondonCanada

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