Abstract:

Objective To measure the atlantoaxial pedicles of 3-6-year-old preschool children by using 3D printing imaging technology, and to provide relevant the oretical basis for the placement of atlantoaxial pedicle screws in preschool children.

Methods The imaging data of 40 children aged 3-6 years who underwent atlantoaxial CT scans in Hebei Children′s Hospital were collected, and atlantoaxial fractures, deformities, tumors and infectious diseases were excluded. A total of 40 cases of atlantoaxial CT imaging data were collected. The 3D model of atlantoaxis was reconstructed by 3D slicer software, and the data parameters such as pedicle length, width, height, width to height ratio were measured. The measured data were grouped by age, namely, group A(aged 3-＜4 years, n=10), group B(aged 4-＜5 years, n=10), group C(aged 5-＜6 years, n=10), and group D(aged 6-<7 years, n=10), and the male to female ratio was 1〖DK〗∶1. The measured data were statistically analyzed.

Results There was no statistical difference between the left and right sides of the atlantoaxial spine and between men and women in the same age group(P＞0.05). Atlantoaxial pedicle length, width and height measurement indexes showed an increasing trend with age, and the difference was statistically significant(P＜0.05). The ratio of the width/height of the lateral mass of the atlas in the preschool age was greater than 1.0, indicating that the width of the atlas pedicle was greater than the height, and the ratio did not change significantly with age. The ratio of the width/height of the axis pedicle in the preschool age was less than 1.0, indicating that the width of the axis pedicle was less than the height, but the ratio did not change significantly with age.

Conclusion The actual and accurate data of the atlantoaxial pedicle of children can be obtained by using the isometric 3D printing model. According to its measurement data, the atlantoaxial pedicle of preschool children can accommodate a pedicle screw with a minimum diameter of 3.5 mm. Therefore, atlantoaxial disease of preschool children can be fixed with a pedicle screw with a minimum diameter of 3.5 mm, but different screw placement methods are also recommended according to the age.

Key words: Atlantoaxial, child, preschool, printing, three-dimensional