Abnormality of Sagittal Alignment in Children with Restricted Forward Bending Cervical Kyphosis and Thoracic Flat Back

Abstract

Introduction: Locomotor examination has been reported to reveal postural abnormalities, including restricted forward bending in children, malalignment, and spinal deformity. This study aimed to clarify the relationship between thoracic kyphosis angle and cervical kyphosis angle and age-related changes in children with restricted forward bending.

Methods: A total of 105 cases of children with restricted forward bending (straight leg raise < 45°) were examined. Their average age was 11.2 (7-15) years, with 48 girls and 57 boys. For the evaluation, the thoracic kyphosis angle on whole spinal X-ray (AeroDR system) was examined by age and gender.

Results: The average thoracic kyphosis was 21.5°, and the average cervical lordosis was 2.8°. No gender-based difference was noted between both kyphosis angles. There was a correlation between the cervical kyphosis angle and the thoracic kyphosis angle, and cervical lordosis decreased with age. The group with a thoracic kyphosis angle of <22° had a significantly larger cervical kyphosis angle than the group with a thoracic spine kyphosis angle of ≥22°. In the cervical spine, 86% of the cases had a normal average lordosis of ≤17°, and in the thoracic spine, 97% of the cases had a normal average kyphosis of ≤35°. This tendency became remarkable with the increase in age.

Conclusions: The thoracic kyphosis angle and the cervical kyphosis angle are inversely correlated, and it may be possible to determine cervical kyphosis deformity by focusing on the decrease in thoracic kyphosis in children with restricted forward bending revealed upon locomotor examination.