Development and Tensile Investigation of a 3-year-old Cervical Spine Finite Element Model

A 3-year-old cervical spine finite element (FE) model with detailed anatomical and material properties was developed and validated against cadaver tests under dynamic loadings. First, the bone geometry was reconstructed based on high-resolution computed tomography (CT) scans, and the elastic-plastic material was defined to simulate the cortical and cancellous bones. Second, to simulate various ligament tears during dynamic tensile, ligaments failure were defined using force versus displacement curves, which had a sigmoidal shape governed by three control point. To better represent complicated structure of disc, such as nucleus pulposus, annulus fibrosus substrate and four pairs of reinforced fiber lamina, the intervertebral discs were defined using composite materials which combined by viscoelastic material, hill foam material and four pairs of reinforced fiber lamina, respectively. Finally, dynamic tensile experiments in C4-C5 and C0-C7 were used to validate the dynamic ultimate force and displacement of the 3-year-old cervical FE model, revealing that this FE model is capable of predicting intervertebral disc injury and ligament tear. This FE model will contribute to a better understanding of the mechanisms underlying pediatric cervical injuries.