A critical thoracic kyphosis is required to prevent sagittal plane deterioration in selective thoracic fusions in Lenke I and II AIS

Purpose Thoracic hypokyphosis following AIS correction may be associated with reduced lumbar lordosis with potential adverse effects on the global sagittal balance. In the present study, we were interested in how the amount of thoracic kyphosis influences the sagittal profile and balance in selective thoracic (STF) and thoracolumbar fusions.