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 extraand 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.

Construction of the Adjusted Scoliosis 3D Finite Element Model and Biomechanical Analysis under Gravity

“…However, the etiology and progression of AIS are multifaceted and cannot be explained only by the imbalance of stress on the spine. Whether asymmetric loads on the vertebrae and discs are the cause of AIS remains controversial 36,37 …”

“…Whether asymmetric loads on the vertebrae and discs are the cause of AIS remains controversial. 36 , 37 …”

“…Whether asymmetric loads on the vertebrae and discs are the cause of AIS remains controversial. 36,37 Strengths and Limitations There are some limitations in this study: the validity of the FE model is determined by comparing the data with the experimental model. Usually, a suitable experimental model is retrieved from the literature.…”

Convex–concave and anterior–posterior spinal length discrepancies in adolescent idiopathic scoliosis with major right thoracic curves versus matched controls

“…From existing pre-operative computed tomographic (CT) databases, patients with right-sided primary thoracic AIS (Lenke 1-4) and sex-and age matched healthy controls were included [10][11][12][13][14]. These patients received these CT-scans as part of their pre-operative work-up for planning of navigation guided pedicle screw placement, which in that university medical center is part of standard care for all idiopathic scoliosis patients with an indication for posterior instrumentation.…”

Methods and Capabilities of Determination of Rotational-Torsional Changes in the Spine in Patients With Scoliotic Disease

“…Необхідно зазначити, що високотехнологічні методики променевого дослідження, такі як мультиспіральна комп'ютерна томографія й магнітно-резонансна томографія, рідко застосовують для вивчення та оцінювання параметрів викривлення хребта, у зв'язку з тим що вони не дозволяють проводити дослідження в положенні стоячи. До них вдаються лише за наявності больового синдрому або в разі підозри на запальні, пухлинні або дегенеративно-дистрофічні зміни хребта і спинного мозку [26,27,28].…”