Biomechanical Dynamics of Cranial Sutures during Simulated Impulsive Loading

Z Q Zhang,J L Yang

doi:10.1155/2015/596843

Abstract

Background. Cranial sutures are deformable joints between the bones of the skull, bridged by collagen fibres. They function to hold the bones of the skull together while allowing for mechanical stress transmission and deformation. Objective. The aim of this study is to investigate how cranial suture morphology, suture material property, and the arrangement of sutural collagen fibres influence the dynamic responses of the suture and surrounding bone under impulsive loads. Methods. An idealized bone-suture-bone complex was analyzed using a two-dimensional finite element model. A uniform impulsive loading was applied to the complex. Outcome variables of von Mises stress and strain energy were evaluated to characterize the sutures' biomechanical behavior. Results. Parametric studies revealed that the suture strain energy and the patterns of Mises stress in both the suture and surrounding bone were strongly dependent on the suture morphologies. Conclusions. It was concluded that the higher order hierarchical suture morphology, lower suture elastic modulus, and the better collagen fiber orientation must benefit the stress attenuation and energy absorption.

Highlights

Cranial sutures are composite mechanical structures, which typically include two interdigitating components and a thin more compliant interfacial layer [1, 2]
Here, we explore the role of hierarchical design on the underlying fundamental dynamics of bone-suture structure using finite element analysis (FEA) method
Based on the biological suture joints observed in the natural prototypes, the complicated suture morphology can be as simple as a sinusoid or exhibit a complex multiple wavelength pattern and/or a hierarchical fractal-like structure of shorter wavelengths superposed onto longer wavelengths [17, 18]

Summary

Introduction

Cranial sutures are composite mechanical structures, which typically include two interdigitating components (the bones) and a thin more compliant interfacial layer (the collagen fibers) [1, 2]. In the bone-suture structures, geometrical morphology is a key determinant of mechanical and biological functions such as static load transmission, stiffness, strength, and energy absorption. Cranial sutures are deformable joints between the bones of the skull, bridged by collagen fibres They function to hold the bones of the skull together while allowing for mechanical stress transmission and deformation. The aim of this study is to investigate how cranial suture morphology, suture material property, and the arrangement of sutural collagen fibres influence the dynamic responses of the suture and surrounding bone under impulsive loads. It was concluded that the higher order hierarchical suture morphology, lower suture elastic modulus, and the better collagen fiber orientation must benefit the stress attenuation and energy absorption

Objectives

Methods

Results

Conclusion