Purpose or Case Report: Understanding normal parameters of pediatric cervical spine is imperative for early detection of cervical spine injury by computed tomography (CT) post trauma. Young children have a higher biomechanical fulcrum, incomplete ossification, and increased soft tissue laxity which minimizes anatomical distortion on CT [1,2]. The first part of this two part study aims to establish normal cervical joint spaces measurements in non-traumatic pediatric population with particular attention to the lateral atlantodental interval (ADI).
Methods & Materials: We reviewed CT images of 115 pediatric patients between the ages of 0 to 10 years. The bilateral ADI were measured in the coronal plane at the level of the dental center.
Results: A total of 115 non-traumatic cases (55 female, 60 male) were viewed and analyzed. The mean right ADI is 5.3 mm, 95% CI [5.0, 5.5], and 5.2 mm, 95% CI [4.9, 5.4] on the left. The mean difference between the two sides is 0.09 mm. When subdivided by age, the following mean distances for the right and left ADI for a particular age group, respectively, were found to be: 0-12 months, 5.9 mm, 6.0 mm; 13-23 months, 5.8 mm, 5.9 mm; 2 years, 5.7 mm, 6.0 mm; 3-4 years, 5.4 mm, 5.4 mm; 5-6 years, 4.8 mm, 4.9mm; and 7-10 years, 4.9 mm, 4.4 mm. There is a negative correlation between ADI and age.
Conclusions: The first part of our study established normal range for ADI in non-traumatic pediatric patients between the ages of 0 to 10 years. Our results are similar to the limited data currently present in literature for these intervals [3]. Additionally, the asymmetry of ADI is likely attributed to patient positioning, image processing, and atlantoaxial joint rotation. These findings shed light on the next phase of our study where these normal parameters will be used in pediatric trauma cases.

References:
1. Kokoska, Evan R., et al. Characteristics of pediatric cervical spine injuries. Journal of pediatric surgery 36.1 (2001): 100-105.
2. Lee, Jung H., et al. Characteristics of pediatric onset spinal cord injury. Pediatrics international 51.2 (2009): 254-257.
3. Rojas, Carlos A., et al. Evaluation of the C1–C2 articulation on MDCT in healthy children and young adults. American Journal of Roentgenology193.5 (2009): 1388-1392.