Study design: A cross-sectional study of spinal stereoradiographs of adolescents with scoliosis to measure growth.
Objective: To determine the relative contributions of the vertebral bodies and intervertebral discs to the increase in spinal length between T5 and L5, over the age range of 7.5-20 years.
Summary of background data: The progression of spinal deformity (scoliosis) is associated with skeletal growth, but the relative roles of asymmetrical growth and remodeling of the vertebrae and discs during adolescent growth are unclear.
Methods: An existing database of 406 spinal stereoradiographic studies of 188 adolescents with idiopathic scoliosis, aged between 7.5 and 20 years, was used to measure the heights of vertebral bodies and intervertebral discs, and the summation of both (spinal length).
Results: Spinal length was observed to increase from about 250 to 350 mm over this range of ages. Spinal growth was associated with an increase in vertebral height after age 10 years, with minimal if any increase in disc height. The contribution of vertebral and discal height was estimated to be about 17 and 8 mm per year, respectively, at age 7.5 years, but discal height growth was estimated to be effectively zero after age 12 years.
Conclusion: Spinal growth of patients with scoliosis aged between 10 and 20 years occurs almost exclusively by height increases in the vertebrae, not the discs.