Pediatric atlas anatomy and its implications for fracture treatment: an anatomical and radiological study

Neurocirugia (Astur : Engl Ed). 2024 Jul-Aug;35(4):186-195. doi: 10.1016/j.neucie.2024.01.001. Epub 2024 Feb 24.


Introduction and objectives: The objective of the study was: (1) to describe changes in the shape of the atlas during growth, including gender and side differences; (2) to assess the dimension essential for identification of the optimal entry point; (3) to determine the age limit for a safe insertion of 3.5-mm screws into the lateral masses according to our own limiting parameters.

Materials and methods: Dimensions of the atlas were measured on 200 CT scans of the craniocervical junction in individuals aged 0-18 years and on 34 anatomical specimens of the first cervical vertebra (aged 2.5-18 years). Both series were divided according to the gender and age. The values measured on CT scans were used for statistical comparison of data in boys and girls and comparison of the right and left sides.

Results: The atlas reaches its maximum growth rate between 0 and 2 years of age, then the growth decelerates and continues until the age of 18 years. The proportion of dimensions of C1 vertebral foramens changes with age. The youngest children show a relatively greater distance from the left to the right medial pedicle; around the age of 5 the values get even and subsequently the distance from the inner wall of anterior to posterior arch gets relatively greater. The transverse foramen has a slightly oval shape throughout the period of growth. Statistically significant differences between boys and girls were observed primarily between 12 and 18 years of age.

Conclusion: The study has proved adequate size of lateral masses for insertion of 3.5-mm screws in all patients from the age of 5 years. In younger children, the patient´s anatomy should be respected and the surgical technique tailored accordingly.

Keywords: Anatomía del atlas pediátrico; Atlas developmental changes; C1 entry point; Cambios en el desarrollo del atlas; Lateral mass screw; Pediatric atlas anatomy; Punto de entrada C1; Tornillo de masa lateral.

MeSH terms

  • Adolescent
  • Bone Screws
  • Cervical Atlas* / anatomy & histology
  • Cervical Atlas* / diagnostic imaging
  • Cervical Atlas* / surgery
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Infant
  • Infant, Newborn
  • Male
  • Spinal Fractures* / diagnostic imaging
  • Spinal Fractures* / surgery
  • Tomography, X-Ray Computed*