Tensile mechanics of the developing cervical spine.

This study examined the effect of spinal development (developmental age) on the tensile mechanics of the cervical spine. A total of 68 isolated functional spinal units were subjected to tensile loading to document their mechanical response (tensile stiffness and ultimate failure load). Cadaveric baboon specimens, ranging in age from 2 to 26 human-equivalent years, were used due to the limited availability of human tissues in the pediatric age range. Statistically significant correlation was found between developmental age and both tensile stiffness and ultimate failure load. Furthermore, differences in these properties were observed as a function of spinal level. In addition to providing age-related data for the developing spine, our findings suggest that reasonable scaling relationships exist between the adult and the child spine. These relationships provide a basis for scaling adult properties to the child, which may abet the development of pediatric neck injury tolerance values.