CT-based study of vertebral and intravertebral rotation in right thoracic adolescent idiopathic scoliosis

Abstract Purpose To define the longitudinal rotation axis around which individual vertebrae rotate, and to establish the various extra- and intravertebral rotation patterns in thoracic adolescent idiopathic scoliosis (AIS) patients, for better understanding of the 3D development of the rotational deformity. Methods Seventy high-resolution CT scans from an existing database of thoracic AIS patients (Cobb angle: 46°–109°) were included to determine the vertebral axial rotation, rotation radius, intravertebral axial rotation, and local mechanical torsion for each spinal level, using previously validated image processing techniques. Results For all levels, the longitudinal rotation axis, from which the vertebrae rotate away from the midline, was localized posterior to the spine. The axis became closer to the spine at the apex: apex, r = 11.5 ± 5.1 cm versus two levels above (radius = 15.8 ± 8.5 cm; p < 0.001) and beneath (radius = 14.2 ± 8.2 cm; p < 0.001). The vertebral axial rotation, intravertebral axial rotation, and local mechanical torsion of the vertebral bodies were largest at the apex (21.9° ± 7.4°, 8.7° ± 13.5° and 3.0° ± 2.5°) and decreased toward the neutral, junctional zones (p < 0.001). Conclusion In AIS, the vertebrae rotate away around an axis that is localized posterior to the spine. The distance between this axis and the spine is minimal at the apex and increases gradually to the neutral zones. The vertebral axial rotation is accompanied by smaller amounts of intravertebral rotation and local mechanical torsion, which increases toward the apical region. The altered morphology and alignment are important for a better understanding of the 3D pathoanatomical development of AIS and better therapeutic planning for bracing and surgical intervention. Graphic abstract These slides can be retrieved under Electronic Supplementary Material.

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Maximal Axial Vertebral Rotation in Adolescent Idiopathic Scoliosis: Is the Apical Vertebra the Most Rotated?

Global Spine Journal ◽

10.1177/2192568220948830 ◽

2020 ◽

pp. 219256822094883

Author(s):

Kristóf József ◽

Ádám Tibor Schlégl ◽

Máté Burkus ◽

István Márkus ◽

Ian O’Sullivan ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Cobb Angle ◽

Axial Rotation ◽

Cross Sectional Study ◽

Vertebral Rotation ◽

Rank Test ◽

Cross Sectional ◽

Apical Vertebra ◽

Axial Vertebral Rotation

Study Design: Retrospective cross-sectional study. Objectives: It is generally believed that the apical vertebra has the largest axial rotation in adolescent idiopathic scoliosis. We investigated the relationship between apical axial vertebral rotation (apicalAVR) and maximal axial vertebral rotation (maxAVR) in both major and minor curves using biplanar stereo-imaging. Methods: EOS 2D/3D biplanar radiograph images were collected from 332 patients with adolescent idiopathic scoliosis (Cobb angle range 10°-122°, mean age 14.7 years). Based on the X-ray images, with the help of 3D full spine reconstructions Cobb angle, curvature level, apicalAVR and maxAVR were determined. These parameters were also determined for minor curves in Lenke 2, 3, 4, 6 type patients. Maximal thoracic rotation and maximal thoracolumbar/lumbar rotation were calculated. Statistical analysis was performed with descriptive statistics, Shapiro-Wilk test, and Wilcoxon signed-rank test. Results: The apical vertebrae were the most rotated vertebra in only 40.4% of the major curves, and 31.7% in minor curves. MaxAVR significantly exceeded apicalAVR values in the major curves ( P < .001) as well as in minor curves ( P < .001). The 2 parameters differed significantly in each severity group and Lenke type. Conclusions: The apical vertebrae were not the most rotated vertebra in more than half of cases investigated indicating that apicalAVR and maxAVR should be considered as 2 distinct parameters, of which maxAVR fully describes the axial dimension of scoliosis. Furthermore, the substitution of maxAVR for the apicalAVR should be especially avoided in double and triple curves, as the apical vertebra was even less commonly the most rotated in minor curves.

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T1-weighted MR imaging of bone marrow pattern in children with adolescent idiopathic scoliosis: a preliminary study

Journal of Children s Orthopaedics ◽

10.1302/1863-2548.12.180035 ◽

2018 ◽

Vol 12 (2) ◽

pp. 181-186 ◽

Cited By ~ 3

Author(s):

S. I. Shiran ◽

L. Shabtai ◽

L. Ben-Sira ◽

D. Ovadia ◽

S. Wientroub

Keyword(s):

Bone Marrow ◽

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Diagnostic Study ◽

Level Of Evidence ◽

Lenke Classification ◽

Adjacent Disc ◽

Vertebral Bodies ◽

Preliminary Study ◽

Mri Study

Purpose Distinct normal physiological patterns of fat conversion in vertebrae were described both for children and adults. Our aim was to evaluate the T1-weighted bone marrow pattern of the vertebral bodies in various sites along the scoliotic spine of children with adolescent idiopathic scoliosis (AIS). Methods We retrospectively evaluated spine MRI studies of children with AIS. Scoliosis radiographs were assessed for type of curvature according to the Lenke classification. A paediatric neuroradiologist assessed the T1-weighted signal of vertebral bodies in comparison with the adjacent disc and distinct patterns of fatty conversion within the apical and stable vertebral bodies. Statistical assessment was performed. Results MRI study of the spines of 75 children with AIS were assessed, 59 (79%) of whom were female, with an age range of nine to 19 years. The relative overall T1-weighted signal intensity of the vertebral body bone marrow relative to the intervertebral disc was hyperintense in 76% and isointense in 24%. Fatty conversion grade of the stable vertebra was higher than the apex vertebra (p = 0.0001). A significant tendency to have more advanced fat conversion patterns in the apex vertebra up to age 13.5 years old compared with adolescents above that (p = 0.015) was seen. Conclusion This preliminary study suggests a different pattern of bone marrow conversion in AIS from the normal physiologic pattern described in the literature. Whether these changes are secondary to the biomechanics of the curved spine or may suggest that bone marrow maturation rate and content have a role in the pathogenesis of AIS remains to be further researched. Level of Evidence Level III (Diagnostic Study)

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Surgical Correction of Vertebral Axial Rotation in Adolescent Idiopathic Scoliosis

Journal of Spinal Disorders ◽

10.1097/00002517-199606000-00006 ◽

1996 ◽

Vol 9 (3) ◽

pp. 214???219 ◽

Cited By ~ 28

Author(s):

David D. Aronsson ◽

Ian A. F. Stokes ◽

Peter J. Ronchetti ◽

B. Stephens Richards

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Axial Rotation ◽

Surgical Correction

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

Orthopaedic Surgery ◽

10.1111/j.1757-7861.2009.00044.x ◽

2009 ◽

Vol 1 (4) ◽

pp. 300-304 ◽

Cited By ~ 2

Author(s):

Hong-guang Xu ◽

Gui-xing Qiu ◽

Yi-peng Wang ◽

Jian-guo Zhang ◽

Yong Liu ◽

...

Keyword(s):

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Imaging Study ◽

Intervertebral Discs ◽

Vertebral Bodies

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Assessment of adolescent idiopathic scoliosis from body scanner image by finite element simulations

PLoS ONE ◽

10.1371/journal.pone.0243736 ◽

2021 ◽

Vol 16 (2) ◽

pp. e0243736

Author(s):

Alexander T. D. Grünwald ◽

Susmita Roy ◽

Ana Alves-Pinto ◽

Renée Lampe

Keyword(s):

Finite Element ◽

Adolescent Idiopathic Scoliosis ◽

Idiopathic Scoliosis ◽

Vertebral Column ◽

Three Dimensional ◽

Axial Rotation ◽

Patient Specific ◽

X Rays ◽

Spinal Curvatures ◽

Body Scanner

Adolescent idiopathic scoliosis, is a three-dimensional spinal deformity characterized by lateral curvature and axial rotation around the vertical body axis of the spine, the cause of which is yet unknown. The fast progression entails regular clinical monitoring, including X-rays. Here we present an approach to evaluate scoliosis from the three-dimensional image of a patient’s torso, captured by an ionizing radiation free body scanner, in combination with a model of the ribcage and spine. A skeletal structure of the ribcage and vertebral column was modelled with computer aided designed software and was used as an initial structure for macroscopic finite element method simulations. The basic vertebral column model was created for an adult female in an upright position. The model was then used to simulate the patient specific scoliotic spine configurations. The simulations showed that a lateral translation of a vertebral body results in an effective axial rotation and could reproduce the spinal curvatures. The combined method of three-dimensional body scan and finite element model simulations thus provide quantitative anatomical information about the position, rotation and inclination of the thoracic and lumbar vertebrae within a three-dimensional torso. Furthermore, the simulations showed unequal distributions of stress and strain profiles across the intervertebral discs, due to their distortions, which might help to further understand the pathogenesis of scoliosis.

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