Developmental anatomy study of the morphological characteristics of the sacral neurocentral synchondrosis in children.

Abstract

To study changes in the morphological indicators of sacral Neurocentral synchondrosis (NCS) in normal children aged 1-5, explore the growth and development patterns of sacral spine NCS with age. 100 normal pelvic CT images of 1-5-year-old children were collected and divided into 5 groups of 20 cases each. The images in DICOM format were imported into Mimics 21.0 software. The morphological indices of sacral NCS were measured using the Measurements toolbar, and statistical analysis was conducted. The closure of NCS in the sacral vertebra S_1-3 shows a clear pattern. S₃ closes earliest (75% closure rate in the Age 1 group, ≥ 95% in the Age 2 group), S₂ closes next and rapidly (15% in the Age 1 group, rising to 80% in the Age 2 group), and S₁ closes last (starting closure in the Age 3 group, reaching 55% in the Age 5 group). In the Age 1-5 groups, the sagittal diameter, perimeter, and area of NCS-S₁ first increase and then gradually decrease, peaking in the Age 2 group; the transverse diameter increases slowly until the Age 4 group and then decreases. The morphological indicators of NCS for S₂ and S₃ continuously decrease, reaching the lowest values by the Age 2 group. The closure time of the sacral NCS follows the order S₃ < S₂ < S₁. In children aged 1-5 years, sacral NCS undergoes segmental rapid ossification, with ossification progressing from the periphery toward the center, exhibiting a developmental pattern characterized by "early peak-rapid closure."