Skip Navigation LinksHome > September 01, 2014 - Volume 39 - Issue 19 > Three-Dimensional Characterization of Torsion and Asymmetry...
Spine:
doi: 10.1097/BRS.0000000000000467
Deformity

Three-Dimensional Characterization of Torsion and Asymmetry of the Intervertebral Discs Versus Vertebral Bodies in Adolescent Idiopathic Scoliosis

Schlösser, Tom P.C. MD*; van Stralen, Marijn PhD; Brink, Rob C. BSc*; Chu, Winnie C. W. MD; Lam, Tsz-Ping FRCSEd§; Vincken, Koen L. PhD; Castelein, René M. MD, PhD*; Cheng, Jack C. Y. MD, FRCSEd§

Collapse Box

Abstract

Study Design. Cross-sectional study.

Objective. To compare the relative contribution of the vertebral bodies and intervertebral discs with the 3-dimensional spinal deformity in adolescent idiopathic scoliosis.

Summary of Background Data. There is an ongoing discussion about the causal role of skeletal growth processes in the etiopathogenesis of adolescent idiopathic scoliosis. Contradictory findings have been reported on the individual contribution of the vertebral bodies as compared with the discs to the coronal deformity. As far as we know, the true 3-dimensional deformity of the discs and vertebral bodies have not yet been described.

Methods. High-resolution computed tomographic scans of 77 patients with severe adolescent idiopathic scoliosis were included. Torsion and anterior-posterior and right-left asymmetry of each individual vertebral body and intervertebral disc were studied from T2 to L5, using semiautomatic analysis software. True transverse sections were reconstructed along the anterior-posterior and right-left axis of all endplates. These “endplate-vectors” were calculated semiautomatically, taking rotation and tilt into account. Torsion was defined as the difference in axial rotation between 2 subsequent endplates. Asymmetry was defined as the relative anterior-posterior or right-left height difference of the discs and the vertebrae.

Results. There were at least 3 times more torsion, anterior overgrowth, and coronal wedging in the discs than in the vertebrae in the thoracic as well as in the (thoraco) lumbar curves (P < 0.001). These values correlated significantly with the Cobb angle (r ≥ 0.37; P < 0.001). Anterior overgrowth and coronal asymmetry were greater in the apical regions whereas torsion was most pronounced in the transitional segments between the curves.

Conclusion. The discs contribute more to 3-D deformity than the bony structures, and there is significant regional variability. This suggests an adaptive rather than an active phenomenon.

Level of Evidence: 2

© 2014 by Lippincott Williams & Wilkins

Follow Us!

  

Login

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.