Cortical and trabecular morphometric properties of the human calvarium

Kevin Adanty; Karyne N Rabey; Michael R Doschak; Kapil B Bhagavathula; James D Hogan; Dan L Romanyk; Samer Adeeb; Simon Ouellet; Thomas A Plaisted; Sikhanda S Satapathy; Christopher R Dennison

doi:10.1016/j.bone.2021.115931

Cortical and trabecular morphometric properties of the human calvarium

Bone. 2021 Jul:148:115931. doi: 10.1016/j.bone.2021.115931. Epub 2021 Mar 23.

Authors

Affiliations

¹ The Biomedical Instrumentation Laboratory, Department of Mechanical Engineering, University of Alberta, Postal Address: 10-203 Donadeo Innovation Centre for Engineering, 9211-116 Street NW, Edmonton T6G 1H9, Alberta, Canada; Department of Mechanical Engineering, University of Alberta, Postal Address: 10-203 Donadeo Innovation Centre for Engineering, 9211-116 Street NW, Edmonton T6G 1H9, Alberta, Canada. Electronic address: adanty@ualberta.ca.
² Department of Surgery, Division of Anatomy, University of Alberta. Postal Address: 2J2.00 WC Mackenzie Health Sciences Centre, 8440-112 St. NW, Edmonton T6G 2R7, Alberta, Canada; Department of Anthropology, Faculty of Arts, University of Alberta. Postal Address: 13-15 Tory Building, Edmonton T6G 2H4, Alberta, Canada. Electronic address: rabey@ualberta.ca.
³ Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta. Postal Address: 2-35, Medical Sciences Building, 8613 - 114 Street, Edmonton T6G 2H7, Alberta, Canada. Electronic address: mdoschak@ualberta.ca.
⁴ Department of Mechanical Engineering, University of Alberta, Postal Address: 10-203 Donadeo Innovation Centre for Engineering, 9211-116 Street NW, Edmonton T6G 1H9, Alberta, Canada. Electronic address: kapil.bharadwaj@ualberta.ca.
⁵ Department of Mechanical Engineering, University of Alberta, Postal Address: 10-203 Donadeo Innovation Centre for Engineering, 9211-116 Street NW, Edmonton T6G 1H9, Alberta, Canada. Electronic address: jdhogan@ualberta.ca.
⁶ Department of Mechanical Engineering, University of Alberta, Postal Address: 10-203 Donadeo Innovation Centre for Engineering, 9211-116 Street NW, Edmonton T6G 1H9, Alberta, Canada. Electronic address: dromanyk@ualberta.ca.
⁷ Department of Civil and Environmental Engineering, University of Alberta, Postal Address: 7-203 Danadeo Innovation Centre for Engineering, 9211-116 Street NW, Edmonton T6G 1H9, Alberta, Canada. Electronic address: samer.adeeb@ualberta.ca.
⁸ Defence Research and Development Canada, Postal Address: Valcartier Research Centre, 2459, Route de la Bravoure, Quebec City, Quebec G3J 1X5, Canada. Electronic address: Simon.Ouellet@drdc-rddc.gc.ca.
⁹ US Army Combat Capabilities Development Command - Army Research Laboratory, Aberdeen Proving Ground, MD 21005, United States of America. Electronic address: thomas.a.plaisted.civ@mail.mil.
¹⁰ US Army Combat Capabilities Development Command - Army Research Laboratory, Aberdeen Proving Ground, MD 21005, United States of America. Electronic address: sikhanda.s.satapathy.civ@mail.mil.
¹¹ The Biomedical Instrumentation Laboratory, Department of Mechanical Engineering, University of Alberta, Postal Address: 10-203 Donadeo Innovation Centre for Engineering, 9211-116 Street NW, Edmonton T6G 1H9, Alberta, Canada; Department of Mechanical Engineering, University of Alberta, Postal Address: 10-203 Donadeo Innovation Centre for Engineering, 9211-116 Street NW, Edmonton T6G 1H9, Alberta, Canada. Electronic address: cdenniso@ualberta.ca.

PMID: 33766803
DOI: 10.1016/j.bone.2021.115931

Abstract

There is currently a gap in the literature that quantitatively describes the complex bone microarchitecture within the diploë (trabecular bone) and cortical layers of the human calvarium. The purpose of this study was to determine the morphometric properties of the diploë and cortical tables of the human calvarium in which key interacting factors of sex, location on the calvarium, and layers of the sandwich structure were considered. Micro-computed tomography (micro-CT) was utilized to capture images at 18 μm resolution of male (n = 26) and female (n = 24) embalmed calvarium specimens in the frontal and parietal regions (N = 50). All images were post-processed and analyzed using vendor bundled CT-Analyzer software to determine the morphometric properties of the diploë and cortical layers. A two-way mixed (repeated measures) analysis of variance (ANOVA) was used to determine diploë morphometric properties accounting for factors of sex and location. A three-way mixed ANOVA was performed to determine cortical morphometric properties accounting for factors of cortical layer (inner and outer table), sex, and location. The study revealed no two-way interaction effects between sex and location on the diploë morphometry except for fractal dimension. Trabecular thickness and separation in the diploë were significantly greater in the male specimens; however, females showed a greater number of trabeculae and fractal dimension on average. Parietal specimens revealed a greater porosity, trabecular separation, and deviation from an ideal plate structure, but a lesser number of trabeculae and connectivity compared to the frontal location. Additionally, the study observed a lower density and greater porosity in the inner cortical layer than the outer which may be due to clear distinctions between each layer's physiological environment. The study provides valuable insight into the quantitative morphometry of the calvarium in which finite element modelers of the skull can refer to when designing detailed heterogenous or subject-specific skull models to effectively predict injury. Furthermore, this study contributes towards the recent developments on physical surrogate models of the skull which require approximate measures of calvarium bone architecture in order to effectively fabricate a model and then accurately simulate a traumatic head impact event.

Keywords: Bone morphometry; Cortical table; Diploë; Human calvarium; Micro-computed tomography (micro-CT).

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Bone Density
Female
Humans
Male
Models, Theoretical*
Porosity
Skull* / diagnostic imaging
X-Ray Microtomography