Imaging study of wedge changes in the vertebral bodies and intervertebral discs in adolescent idiopathic scoliosis.

Objective: To observe wedge changes in the vertebral bodies and intervertebral discs in progressive adolescent idiopathic scoliosis before and after conservative treatment with braces, and to explore the correlation between wedge changes in the vertebral bodies or intervertebral discs and scoliosis curves.
Methods: Thirty-seven consecutive patients with adolescent idiopathic scoliosis were included in this study from June 2001 to August 2003. There were 31 female and 6 male patients, with an average age of 14.9 years. According to the Peking Union Medical College (PUMC) grading system, eight cases were Ia, three Ib, five Ic, twelve IIb1, three IIb2, three IIc1, one IIc3, and two IId1. Wedge changes in the vertebral bodies and intervertebral discs, and the scoliosis angles were measured by radiographic evaluation before conservative treatment with braces and before surgery.
Results: In the mature patients (Risser sign IV, V, menarche two years or more previously), wedge changes in the vertebral bodies and intervertebral discs worsened with curve progression, and were poorly correlated with the degree of curve (r= 0.17). But in the developmentally immature patients (Risser sign 0-III, pre-menarche), there was a significant correlation with the degree of curve (r= 0.69). Wedge changes in the vertebral bodies and intervertebral discs worsened with curve progression, and were significantly correlated with the degree of curve.
Conclusion: Wedge changes in the vertebral bodies and intervertebral discs have a positive correlation with degree of curve, which indicates that asymmetric growth of the cartilaginous endplate might be the primary cause of wedge change in the vertebral bodies.
(© 2009 Tianjin Hospital and Blackwell Publishing Asia Pty Ltd.)