Purpose - to study alterations in the bony structures in cases of congenital deformity of the thoracic spine combined with malsegmentation of lateral surfaces of vertebrae due to pathological processes during growth period of childern and to find correlation with above alterations.

Material and methods. The study included 30 patients with congenital deformity of thoracic spine combined with malsegmentation of lateral surfaces of vertebrae. Age of patients ranged from 3 to 10 years (mean of 7 years). Gender distribution - 19 female and 11 male patients. All patients underwent imaging examination including spine roentgenography in two standard views in prone position as well as computer tomography.

Results. Magnitude of deformity scoliotic curve was 67 degrees (45-88 degrees) and of pathological thoracic lordosis - 23 degrees (18-27 degrees). Mean number of block vertebral motion segments included into the main deformity curve was 6 (3-8). Mean distance between the outline of lateral vertebral surface and lateral outline of projection of curve root of apical vertebra on convex side of deformity (AB) was 6 mm (4-10 mm). Correlation analysis demonstrated that AB distance mostly depended on the number of vertebral motion segments included into the block along non-segmental area: Pearson coefficient 0.67. Based on CT scans the authors observed no rotation component of bodies' deformity along the non-segmental area.

Conclusion. Children with congenital thoracic spine deformity along with malsegmentation of lateral surfaces of vertebrae feature pathological lordosis in affected zone. Alterations in the bony structures result from asymmetric growth of one half of the vertebral body at the level of non-segmentation. Asymmetry severity has a strong correlation dependency from the number of vertebral bodies included in the block along the non-segmental area.