Large cortical bone pores in the tibia are associated with proximal femur strength

Gianluca Iori, Johannes Schneider, Andreas Reisinger, Frans Heyer, Laura Peralta, Caroline Wyers, Melanie Graesel, Reinhard Barkmann, Claus Glueer, J. van den Bergh, Dieter Pahr, Kay Raum*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

16 Citations (Web of Science)

Abstract

Alterations of structure and density of cortical bone are associated with fragility fractures and can be assessed in vivo in humans at the tibia. Bone remodeling deficits in aging women have been recently linked to an increase in size of cortical pores. In this ex vivo study, we characterized the cortical microarchitecture of 19 tibiae from human donors (aged 69 to 94 years) to address, whether this can reflect impairments of the mechanical competence of the proximal femur, i.e., a major fracture site in osteoporosis. Scanning acoustic microscopy (12 mu m pixel size) provided reference microstructural measurements at the left tibia, while the bone vBMD at this site was obtained using microcomputed tomography (microCT). The areal bone mineral density of both left and right femoral necks (aBMD(neck)) was measured by dual-energy X-ray absorptiometry (DXA), while homogenized nonlinear finite element models based on high-resolution peripheral quantitative computed tomography provided hip stiffness and strength for one-legged standing and sideways falling loads. Hip strength was associated with aBMD(neck) (r = 0.74 to 0.78), with tibial cortical thickness (r = 0.81) and with measurements of the tibial cross-sectional geometry (r = 0.48 to 0.73) of the same leg. Tibial vBMD was associated with hip strength only for standing loads (r = 0.59 to 0.65). Cortical porosity (Ct.Po) of the tibia was not associated with any of the femoral parameters. However, the proportion of Ct.Po attributable to large pores (diameter > 100 mu m) was associated with hip strength in both standing (r = -0.61) and falling (r = 0.48) conditions. When added to aBMD(neck), the prevalence of large pores could explain up to 17% of the femur ultimate force. In conclusion, microstructural characteristics of the tibia reflect hip strength as well as femoral DXA, but it remains to be tested whether such properties can be measured in vivo.

Original languageEnglish
Article number0215405
Pages (from-to)1-18
Number of pages18
JournalPLOS ONE
Volume14
Issue number4
DOIs
Publication statusPublished - 17 Apr 2019

Keywords

  • FEMORAL FRACTURE LOAD
  • HIP FRACTURE
  • DISTAL RADIUS
  • HR-PQCT
  • MICROARCHITECTURAL PARAMETERS
  • HIGH-RESOLUTION
  • POROSITY
  • WOMEN
  • FRAGILITY
  • BMD

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