Cervical Spinal Canal Plasticity in Children as Determined by the Vertebral Body Ratio Technique

The sagittal cervical canal measurement from a plain spine radiography is easy to obtain and has a smaller range than the interpedicular distance. In an effort to standardize the sagittal measurement, a canal ratio, using the vertebral body diameter, has been formulated. If this method is to be used in the pediatric spine, the effect of the growing neuraxis must be considered. Lateral cervical spine radiographs of 301 normal children and adults were evaluated and grouped according to age. The canal ratio measurement demonstrated a consistent decrease through to the adult groups. Adjacent groups showed statistically significant decreases with age in all groups tested other than the oldest two groups. With the pediatric spinal canal vulnerable to various intracanalicular influences, the canal ratio may reflect early disease processes.