Periosteal biaxial residual strains correlate with bone specific growth rates in chick embryos

Abstract

It has been proposed that periosteal residual tensile strains influence periosteal bone apposition and endochondral ossification. The role of bone growth rates on the development of residual strains is not well known. This study examined the relationships between specific growth rate and residual strains in chick tibiotarsi. We measured length and circumference during embryonic days 11–20 using microCT. Bones grew faster in length, with longitudinal and circumferential specific growth rates decreasing from 17 to 9% and 14 to 8% per day, respectively. To calculate residual strains, opening dimensions of incisions through the periosteum were analysed using finite element techniques. Results indicate that Poisson's ratio for an isotropic material model is between 0 and 0.04. For the model with Poisson's ratio 0.03, longitudinal and circumferential residual strains decreased from 46.2 to 29.3% and 10.6 to 3.9%, respectively, during embryonic days 14–20. Specific growth rates and residual strains were positively correlated (p < 0.05).

Keywords:

• periosteum
• chick embryo
• residual strain
• growth rate
• mechanobiology
• bone development

Acknowledgements

The authors thank Lampros Kourtis, Derek Lindsey, Joe Haemer, Dana Carpenter, Bob Spilker, Dolff van der Heide, Philipp Leucht, Gary Beaupre, Emily Arnsdorf, Diane Wagner, Marc Levenston and Minal Tapadia. This study was funded by the Bone and Joint Center (VA Palo Alto Health Care System, CA) an NIH Regenerative Medicine Training Grant (T90 DK070103-02), an NSF graduate research fellowship, and the Oak Foundation.