HR-pQCT-based homogenised finite element models provide quantitative predictions of experimental vertebral body stiffness and strength with the same accuracy as μFE models

Comput Methods Biomech Biomed Engin. 2012;15(7):711-20. doi: 10.1080/10255842.2011.556627. Epub 2011 May 24.

Abstract

This study validated two different high-resolution peripheral quantitative computer tomography (HR-pQCT)-based finite element (FE) approaches, enhanced homogenised continuum-level (hFE) and micro-finite element (μFE) models, by comparing them with compression test results of vertebral body sections. Thirty-five vertebral body sections were prepared by removing endplates and posterior elements, scanned with HR-pQCT and tested in compression up to failure. Linear hFE and μFE models were created from segmented and grey-level CT images, and apparent model stiffness values were compared with experimental stiffness as well as strength results. Experimental and numerical apparent elastic properties based on grey-level/segmented CT images (N=35) correlated well for μFE (r2=0.748/0.842) and hFE models (r2=0.741/0.864). Vertebral section stiffness values from the linear μFE/hFE models estimated experimental ultimate apparent strength very well (r2=0.920/0.927). Calibrated hFE models were able to predict quantitatively apparent stiffness with the same accuracy as μFE models. However, hFE models needed no back-calculation of a tissue modulus or any kind of fitting and were computationally much cheaper.

Publication types

  • Comparative Study
  • Evaluation Study
  • Validation Study

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Biomechanical Phenomena
  • Bone Density
  • Cadaver
  • Compressive Strength / physiology
  • Elasticity / physiology
  • Female
  • Finite Element Analysis
  • Humans
  • In Vitro Techniques
  • Linear Models
  • Male
  • Middle Aged
  • Models, Biological*
  • Spine / diagnostic imaging
  • Spine / physiology*
  • Tomography, X-Ray Computed