In this study, three-dimensional (3D) nonlinear finite element models (FEM's) of age-specific one-year-old, three-year-old, and six-year-old pediatric human cervical spine (C4-C5-C6) structures were developed. The adult human cervical spine model was modified to create one, three and six year old pediatric spines by incorporating the local geometrical and material characteristics of the developmental anatomy. The biomechanical force-displacement/moment-rotation responses of the pediatric structures under compression, flexion and extension forces were nonlinear. All pediatric structures were consistently more flexible than the adult spine under all loading modes and at all load levels. The responses of the pediatric structures were compared to the well-developed adult structure using three approaches: (1) pure overall structural scaling (reduce size) of the adult model without incorporating the local component geometrical and material property changes; (2) using three separate age-specific pediatric models incorporating local component geometrical and material property changes; and (3) using the three pediatric models constructed and combining the overall structural scaling effects. The present findings of significant increase in biomechanical response due to local geometry and material property changes emphasize the need to consider the developmental anatomical features in pediatric structures to better predict their biomechanical behaviour. (A)
Abstract