Mechanical Competence and Bone Quality Develop During Skeletal Growth

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal

14 Scopus Citations
View graph of relations

Author(s)

  • Elizabeth A Zimmermann
  • Christoph Riedel
  • Felix N Schmidt
  • Kilian E Stockhausen
  • Yuriy Chushkin
  • Eric Schaible
  • Bernd Gludovatz
  • Eik Vettorazzi
  • Federico Zontone
  • Klaus Püschel
  • Michael Amling
  • Björn Busse

Detail(s)

Original languageEnglish
Pages (from-to)1461-1472
Journal / PublicationJournal of Bone and Mineral Research
Volume34
Issue number8
Online published26 Mar 2019
Publication statusPublished - Aug 2019
Externally publishedYes

Abstract

Bone fracture risk is influenced by bone quality, which encompasses bone's composition as well as its multiscale organization and architecture. Aging and disease deteriorate bone quality, leading to reduced mechanical properties and higher fracture incidence. Largely unexplored is how bone quality and mechanical competence progress during longitudinal bone growth. Human femoral cortical bone was acquired from fetal (n = 1), infantile (n = 3), and 2- to 14-year-old cases (n = 4) at the mid-diaphysis. Bone quality was assessed in terms of bone structure, osteocyte characteristics, mineralization, and collagen orientation. The mechanical properties were investigated by measuring tensile deformation at multiple length scales via synchrotron X-ray diffraction. We find dramatic differences in mechanical resistance with age. Specifically, cortical bone in 2- to 14-year-old cases exhibits a 160% greater stiffness and 83% higher strength than fetal/infantile cases. The higher mechanical resistance of the 2- to 14-year-old cases is associated with advantageous bone quality, specifically higher bone volume fraction, better micronscale organization (woven versus lamellar), and higher mean mineralization compared with fetal/infantile cases. Our study reveals that bone quality is superior after remodeling/modeling processes convert the primary woven bone structure to lamellar bone. In this cohort of female children, the microstructural differences at the femoral diaphysis were apparent between the 1- to 2-year-old cases. Indeed, the lamellar bone in 2- to 14-year-old cases had a superior structural organization (collagen and osteocyte characteristics) and composition for resisting deformation and fracture than fetal/infantile bone. Mechanistically, the changes in bone quality during longitudinal bone growth lead to higher fracture resistance because collagen fibrils are better aligned to resist tensile forces, while elevated mean mineralization reinforces the collagen scaffold. Thus, our results reveal inherent weaknesses of the fetal/infantile skeleton signifying its inferior bone quality. These results have implications for pediatric fracture risk, as bone produced at ossification centers during children's longitudinal bone growth could display similarly weak points.

Research Area(s)

  • ANALYSIS/QUANTITATION OF BONE, BONE MODELING, BONE QUALITY, BONE REMODELING, HISTOMORPHOMETRY, OSTEOCYTES

Citation Format(s)

Mechanical Competence and Bone Quality Develop During Skeletal Growth. / Zimmermann, Elizabeth A; Riedel, Christoph; Schmidt, Felix N; Stockhausen, Kilian E; Chushkin, Yuriy; Schaible, Eric; Gludovatz, Bernd; Vettorazzi, Eik; Zontone, Federico; Püschel, Klaus; Amling, Michael; Ritchie, Robert O; Busse, Björn.

In: Journal of Bone and Mineral Research, Vol. 34, No. 8, 08.2019, p. 1461-1472.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journal