Changes in Regional and Global Sagittal Parameters of the Spine during Growth in the Pediatric Population

Study Design: Cross-sectional study. Objectives: To demonstrate normative values for various parameters of spinal sagittal global balance in the pediatric population and elucidate whether these parameters change during growth. Summary of Literature Review: While sagittal parameters for adults have been thoroughly evaluated, relatively few studies have reported normal values and changing trends of sagittal parameters in the pediatric population. Materials and Methods: A total of 200 patients aged 5–20 years were evaluated. Cervical lordosis, thoracic kyphosis, lumbar lordosis, pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), pelvic incidence–lumbar lordosis (PI-LL), C2–C7 sagittal vertical axis (SVA), C7 SVA, T1 pelvic angle (T1PA), and the spinosacral angle (SSA) were assessed. Results: Significant positive correlations were found between age and PI (r=0.297, p<0.001), SS (r=0.184, p=0.009), and PT (r=0.203, p=0.004). Among the global sagittal parameters, T1PA (r=0.345, p<0.001) demonstrated a significant association with age, whereas C7 SVA (r=−0.053, p=0.464) and SSA (r=−0.029, p=0.194) were not significantly associated. Furthermore, PI-LL was significantly smaller in the ≥12-year age group than that in the ≤11-year age group (p=0.037). Conclusions: In conclusion, PI, PT, and SS increase during growth owing to the increasing size of the pelvis. T1PA accordingly increases with an increase in pelvic parameters, whereas no other global sagittal parameters, such as C7 SVA or SSA, change during childhood. The changing trends and normative values of each parameter demonstrated in the present study should be considered when planning long-level fusion operations for pediatric patients.