Time-Dependent Collagen Fibered Structure in the Early Distraction Callus: Imaging Characterization and Mathematical Modeling

Ann Biomed Eng. 2022 Dec;50(12):1798-1809. doi: 10.1007/s10439-022-02992-3. Epub 2022 Jun 22.

Abstract

Collagen is a ubiquitous protein present in regenerating bone tissues that experiences multiple biological phenomena during distraction osteogenesis until the deposition of phosphate crystals. This work combines fluorescence techniques and mathematical modeling to shed light on the mechano-structural processes behind the maturation and accommodation-to-mineralization of the callus tissue. Ovine metatarsal bone calluses were analyzed through confocal images at different stages of the early distraction osteogenesis process, quantifying the fiber orientation distribution and mean intensity as fiber density measure. Likewise, a mathematical model based on the experimental data was defined to micromechanically characterize the apparent stiffening of the tissue within the distracted callus. A reorganization of the fibers around the distraction axis and increased fiber density were found as the bone fragments were gradually separated. Given the degree of significance between the mathematical model and previous in vivo data, reorganization, densification, and bundle maturation phenomena seem to explain the apparent mechanical maturation observed in the tissue theoretically.

Keywords: Collagen; Confocal microscopy; Distraction osteogenesis; Mathematical modeling; Mineralization; Orientation.

MeSH terms

  • Animals
  • Bone Regeneration
  • Bony Callus / diagnostic imaging
  • Diagnostic Imaging
  • Models, Theoretical
  • Osteogenesis*
  • Osteogenesis, Distraction* / methods
  • Sheep