Article thumbnail

Influence of Vertical Trabeculae on the Compressive Strength of the Human Vertebra

By Aaron J Fields, Gideon L Lee, X Sherry Liu, Michael G Jekir, X Edward Guo and Tony M Keaveny

Abstract

Vertebral strength, a key etiologic factor of osteoporotic fracture, may be affected by the relative amount of vertically oriented trabeculae. To better understand this issue, we performed experimental compression testing, high-resolution micro–computed tomography (µCT), and micro–finite-element analysis on 16 elderly human thoracic ninth (T9) whole vertebral bodies (ages 77.5 ± 10.1 years). Individual trabeculae segmentation of the µCT images was used to classify the trabeculae by their orientation. We found that the bone volume fraction (BV/TV) of just the vertical trabeculae accounted for substantially more of the observed variation in measured vertebral strength than did the bone volume fraction of all trabeculae (r2 = 0.83 versus 0.59, p < .005). The bone volume fraction of the oblique or horizontal trabeculae was not associated with vertebral strength. Finite-element analysis indicated that removal of the cortical shell did not appreciably alter these trends; it also revealed that the major load paths occur through parallel columns of vertically oriented bone. Taken together, these findings suggest that variation in vertebral strength across individuals is due primarily to variations in the bone volume fraction of vertical trabeculae. The vertical tissue fraction, a new bone quality parameter that we introduced to reflect these findings, was both a significant predictor of vertebral strength alone (r2 = 0.81) and after accounting for variations in total bone volume fraction in multiple regression (total R2 = 0.93). We conclude that the vertical tissue fraction is a potentially powerful microarchitectural determinant of vertebral strength. © 2011 American Society for Bone and Mineral Research

Topics: Original Article
Publisher: Wiley Subscription Services, Inc., A Wiley Company
OAI identifier: oai:pubmedcentral.nih.gov:3179351
Provided by: PubMed Central

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.

Suggested articles

Citations

  1. (2006). A biomechanical perspective on bone quality.
  2. (2008). A patient-specific finite element methodology to predict damage accumulation in vertebral bodiesunder axial compression, sagittal flexion andcombinedloads. Comput Methods Biomech Biomed Engin.
  3. (2002). Age-related differences between thinning of horizontal and vertical trabeculae in human lumbar bone as assessed by a new computerized method.
  4. (2007). Alterations of cortical and trabecular architecture are associated with fractures in postmenopausal women, partially independent of decreased BMD measured by DXA: the OFELY study. J Bone Miner Res.
  5. BellGH,DunbarO,BeckJS,GibbA.Variationsinstrengthofvertebrae with age and their relation to osteoporosis. Calcif Tissue Res.
  6. Biomechanical consequences of an isolated overload on the human vertebral body.
  7. (1999). Biomechanical effects of intraspecimen variations in trabecular architecture: A three-dimensional finite element study.
  8. (1991). Classification of vertebral fractures. J Bone Miner Res.
  9. (2007). Comparison of quantitative computed tomography-based measuresin predictingvertebralcompressive strength.
  10. (2008). Completevolumetric decomposition of individual trabecular plates and rods and its morphological correlations with anisotropic elastic moduli in human trabecular
  11. (1998). Contribution of the cortical shell of vertebrae to mechanical behaviour of the lumbar vertebrae with implications for predicting fracture
  12. (2009). Contribution of trabecular and cortical components to biomechanical behavior of human vertebrae: an ex-vivo study. J Bone Miner Res.
  13. (1985). Correlation between the compressive strength of iliac and vertebral trabecular bone in normal individuals.
  14. (2006). Corticalandtrabecular load sharing in the human vertebral body. J Bone Miner Res.
  15. Effect of bone distribution on vertebral strength: assessment with patient-specific nonlinear finite element analysis.
  16. (2010). Effects of trabecular type and orientation on microdamage susceptibility in trabecular bone.
  17. (1988). Functional biomechanics of the thoracolumbar vertebral cortex. Clin Biomech.
  18. Importance of individual rods and plates in the assessment of bone quality and their contribution to bone stiffness. J Bone Miner Res.
  19. Improvements in vertebral body strength under teriparatide treatment assessed in vivo by finite elementanalysis:resultsfromtheEUROFORSstudy.JBoneMinerRes.
  20. (2009). Individual trabeculae segmentation based morphological analyses of registered HR-pQCT and mCT images of human tibial bone. Trans Orthop Res Soc.
  21. Intervertebral disc degeneration can lead to ‘‘stress-shielding’’ of the anterior vertebral body: a cause of osteoporotic vertebral fracture?
  22. (2006). Intervertebral disc degeneration can predispose to anterior vertebral fractures in the thoracolumbar spine. J Bone Miner Res.
  23. (2003). Is the paradigm shifting?
  24. (2007). Locations of bone tissue at high risk of initial failure during compressive loading of the human vertebral body.
  25. (1999). Measurement ofintraspecimenvariationsinvertebralcancellousbonearchitecture.
  26. Micromechanical analyses of vertebral trabecular bone based on individual trabeculae segmentation of plates and rods.
  27. (2005). Multi-detector row CT imaging of vertebral microstructure for evaluation of fracture risk. J Bone Miner Res.
  28. (2009). Multi-scale modeling of the human vertebral body: comparison of micro-CT based high-resolution and continuum-level models. Pac Symp Biocomput.
  29. (1989). Prediction of vertebralstrength by dual photon-absorptiometry and quantitative computed-tomography. Calcif Tissue Int.
  30. Regionalvariation in vertebral bone morphology andits contributionto vertebralfracture strength.Bone.
  31. Relationship between axial and bending behaviors of the human thoracolumbar vertebra.
  32. Relative strength of thoracic vertebrae in axial compression versus flexion.
  33. Role of trabecular microarchitecture anditsheterogeneityparametersinthemechanical behaviorofex-vivo human L3 vertebrae. J Bone Miner Res.
  34. (2009). Role of trabecular microarchitecture in whole-verterbal body biomechanical behavior. J Bone Miner Res.
  35. (1993). Role of trabecular morphology in the etiology of age-related vertebral fractures. Calcif Tissue Int.
  36. Simulation of vertebral trabecular bone loss using voxel finite element analysis.
  37. (2009). The influence of boundary conditions and loading mode on high-resolution finite element-computed trabecular tissue properties.
  38. The micro-mechanics of cortical shell removal in the human vertebral body.
  39. (2004). The osteoporotic vertebral structure is well adapted to the loads of daily life, but not to infrequent ‘‘error’’ loads.
  40. The relation between bone-mineral content, experimental compression fractures, and disk degeneration in lumbar vertebrae.
  41. (1969). The relative contribution of trabecular and cortical bone to the strength of human lumbar vertebrae. Calcif Tissue Res.
  42. Trabecular bone structure and strength-remodeling and repair.
  43. Trabecular bone structure obtained from multislice spiral computed tomography of the calcaneus predicts osteoporotic vertebral deformities.
  44. Trabecular bone structure of the distal radius, the calcaneus, and the spine: which site predicts fracture status of the spine best? Invest Radiol.
  45. (2008). Trabecular structure quantified with the MRI-based virtual bone biopsy in postmenopausal women contributes to vertebral deformity burden independent of areal vertebral BMD. J Bone Miner Res.
  46. (2004). Ultrascalable implicit finite element analyses in solid mechanics with over a half a billion degrees of freedom