a Department of Neurosurgery , Medical College of Wisconsin , Milwaukee , Wisconsin.
Traffic Inj Prev. 2014;15(3):287-93. doi: 10.1080/15389588.2013.811719.
Child dummies and injury criteria used in automotive crashworthiness environments are based on scaling from the adult and/or between children of different ages. Cartilage-to-bone ossification, spinal canal and joint developments of the spine, and strength attainments do not grow linearly from birth to maturity. Though this is known to medical professionals, age-based quantitative analyses are needed to accurately model the pediatric spine. The objective of this study was to quantify longitudinal growths of various regions of the first cervical vertebrae, responsible for transmitting the axial load from the base of the skull through the condyles to the neck/torso.
Computed tomography (CT) images of 54 children from one day to 18 years of age were retrospectively used to determine the following geometrical properties: bilateral neurocentral synchondroses widths, the width of posterior synchondrosis, outer and inner anteroposterior and transverse diameters, spinal canal area, and depths of the anterior and posterior arches of the C1 vertebra. Both axial and sagittal CT images were used in the analysis. Sagittal images were used to quantify data for the anterior and posterior arches and axial images were used for all described cross-sectional parameters.
Geometrical properties were extracted and reported for the various parameters at 6 months; one year; 18 months; and 3, 6, and 10 years of age corresponding to the dummy family ages routinely used in motor vehicle crashworthiness research and other applications. The outer transverse diameter ranged from 4.97 to 7.08 cm; outer and inner antero-posterior diameters ranged from 2.99 to 4.18 and 2.19 to 3.03 mm; and spinal canal area ranged from 4.34 to 6.68 mm(2). Other data are given in the body of the article. The growths of the first cervical vertebra quantified in terms of the above variables occurred nonlinearly with age and the degree of nonlinearity depended on the type of the geometrical parameter. Growths did not match with the simple scaling ratios based on the adult spine, used in different studies reported in the current literature.
These early nonlinear and nonuniform age- and local geometry-specific variations should be considered in human finite element models for an accurate transfer of the external load from the atlas to the subaxial spine and to improve their fidelity and biomechanical capabilities.
汽车碰撞安全性环境中使用的儿童假人和损伤标准是基于从成年人或不同年龄的儿童进行缩放。软骨到骨的骨化、脊柱的椎管和关节发育以及力量的获得并不是从出生到成熟呈线性增长的。尽管这是医学专业人员所知道的，但需要基于年龄的定量分析来准确地模拟儿科脊柱。本研究的目的是量化第一颈椎各个区域的纵向生长，这些区域负责将来自颅底的轴向载荷通过髁突传递到颈部/躯干。
回顾性地使用 54 名从一天到 18 岁的儿童的计算机断层扫描（CT）图像来确定以下几何特性：双侧骺软骨核宽度、后骺软骨核宽度、外、内前后径和横径、椎管面积以及 C1 椎体的前后弓深度。分析中同时使用了轴向和矢状 CT 图像。矢状图像用于量化前弓和后弓的数据，而轴向图像用于所有描述的横断截面参数。
提取并报告了各种参数在 6 个月、1 年、18 个月以及 3、6 和 10 岁时的几何特性，这些年龄对应于汽车碰撞安全性研究和其他应用中常规使用的假人家族年龄。外横径范围为 4.97 至 7.08 厘米；外、内前后径范围为 2.99 至 4.18 毫米和 2.19 至 3.03 毫米；椎管面积范围为 4.34 至 6.68 毫米²。其他数据在文章正文中给出。第一颈椎的生长以以上变量来衡量，其随年龄呈非线性变化，非线性程度取决于几何参数的类型。生长情况与当前文献中不同研究中使用的基于成人脊柱的简单缩放比不匹配。
在用于将外部载荷从寰椎准确传递到下颈椎的人体有限元模型中，应考虑这些早期非线性和非均匀的年龄和局部几何特定变化，以提高其逼真度和生物力学能力。
