The Evolution of Sagittal Spinal Alignment in Sitting Position During Childhood.

Study Design: This is a cross-sectional descriptive study.
Objective: The purposes of this study are to describe normative data of the sagittal plane in the sitting position within the pediatric population and document the evolution of sagittal alignment during the growth.
Summary of Background Data: Surgical procedures addressing the deformity aim to make the maximal correction on the coronal and transverse planes and to restore the physiological curves on the sagittal plane. Prerequisite for sagittal plane reconstruction is to know the physiological values.
Methods: Children between 3 and 17 years of age, followed by pediatrics unit for nonskeleton disease with lateral radiographs of the entire spine and pelvis on sitting positions, were included to the study. Children with history of surgery or disease that may affect spine development were excluded. Children were evaluated in 4 age groups (3-6, 7-9, 10-12, and 13-17 yr) in terms of spinal sagittal alignment on sitting position.
Results: Of the screened, 124 children (49 girls, 75 boys) were included. Descriptive statistics of all possible segmental angles were summarized. Thoracic kyphosis and lumbar lordosis values were lower on sitting position than on standing position. Thoracic segmental angulations steadily increased from T1-T2 to midthoracic segments and then decreased in caudal direction. Moreover, lumbar segmental angulations steadily increased in cephalocaudal direction. Sacral slope, L4-S1 angulation, and T1-T12 and T1-S1 distance tend to increase as the age increases.
Conclusion: Sagittal spinal alignment in the sitting position is different than that in the standing position and it changes as the child grows. There is a statistically significant difference between different age groups, especially at the cervicothoracic, thoracolumbar, and lumbosacral junctions. These findings should be taken into consideration for young nonambulatory patients who require spinal instrumentation and/or fusion.
Level of Evidence: 2.