The Development of Kyphosis and Lordosis in the Growing Spine

STUDY DESIGN: A longitudinal cohort study. OBJECTIVE: The aim of this study was to do the analysis of the development of kyphosis and lordosis in the growing spine. SUMMARY OF BACKGROUND DATA: Previous studies have measured kyphosis and lordosis in different ways with differing techniques. None of the previous literature has a truly longitudinal design and there is disagreement as to whether there exists a difference between the development of kyphosis and lordosis between males and females. METHODS: Repeated measures using Integrated Shape Imaging System Integrated Shape Imaging System 2 surface topography over 5 years of a group of children aged 5 to 16 years without spinal deformity. Longitudinal analysis was performed using linear mixed effects modeling. RESULTS: There were 638 measures in 194 children. Both kyphosis and lordosis increased with age in both males and females (P < 0.001 for kyphosis and P = 0.002 for lordosis). There was no statistical difference in the development of kyphosis between males and females (P = 0.149). However, there was a significant difference in lordosis between males and females (P < 0.001) with female lordosis larger than that seen in males. Kyphosis and lordosis increased in a nonlinear fashion with age. CONCLUSION: Kyphosis and lordosis increase as children age. Between males and females there is no difference in the increase in the size of kyphosis, but there is difference in the size of lordosis with females having greater lordosis versus males at the same age. LEVEL OF EVIDENCE: 2.