Evaluation of wedging of lower thoracic and upper lumbar vertebral bodies in the pediatric population.

Objective: Anterior wedging of thoracolumbar vertebral bodies is often seen in children. The purpose of our study was to show whether mild anterior wedging of pediatric thoracolumbar junction vertebral bodies can be seen as a normal variant, rather than as the sequela of trauma.

Materials And Methods: A retrospective review was performed of pediatric abdomen and pelvis CT performed between January 2004 and March 2006, excluding children at high risk for compression fractures. Twenty CT studies were randomly selected for each of five arbitrary age groups: < 3, 4-7, 8-11, 12-14, and 15-17 years (100 total CT studies). Using sagittal reformations, anterior and posterior heights of all T10-L3 vertebral bodies were measured to determine anterior-to-posterior vertebral body height ratio (A:P ratio). Inter- and intraobserver agreement was determined. The lower limit of normal (lower fifth percentile of the distribution) was estimated using quantile regression.

Results: A:P ratio at the thoracolumbar junction was greater than 0.893 in 95% of children. There was no statistically significant correlation between age and the A:P ratio. There was strong intra- and interobserver agreement.

Conclusion: From T10 through L3, 95% of children have an A:P ratio greater than 0.893. This suggests that an A:P ratio less than 0.893 should raise the possibility of vertebral body injury. Because age was not statistically significant with respect to the A:P ratio, this value can be used across all pediatric age groups.