Three-Dimensional Characterization of Torsion and Asymmetry of the Intervertebral Discs Versus Vertebral Bodies in Adolescent Idiopathic Scoliosis (original) (raw)
Related papers
Progression of Vertebral and Spinal Three-Dimensional Deformities in Adolescent Idiopathic Scoliosis
Spine, 2001
Study Design. The evolution of scoliotic descriptors was analyzed from three-dimensionally reconstructed spines and assessed statistically in a group of adolescents with progressive idiopathic scoliosis. Objectives. To conduct an intrasubject longitudinal study quantifying evolution of two-and three-dimensional geometrical descriptors characterizing the scoliotic spine and vertebral deformities. Summary of Background Data. The data available on geometric descriptors usually are based on cross-sectional studies comparing scoliotic configurations of different individuals. The literature reports very few longitudinal studies that evaluated different phases of scoliotic progression in the same patients. Methods. The evolution of regional and local descriptors between two scoliotic visits was analyzed in 28 adolescents with scoliosis. Several statistical analyses were performed to determine how spinal curvatures and vertebral deformities change during scoliosis progression. Results. At the thoracic level, vertebral wedging increases with curve severity in a relatively consistent pattern for most patients with scoliosis. Axial rotation mainly increases toward curve convexity with scoliosis severity, worsening the progression of vertebral body deformities. No consistent evolution is associated with the angular orientation of the maximum wedging. Thoracic kyphosis varies considerably among subjects. Both increasing and decreasing kyphosis are observed in nonnegligible proportions. A decrease in kyphosis is associated with a shift in the plane of maximum deformity toward the frontal plane, which worsens the three-dimensional shape of the spine. Conclusions. The results of this study challenge the existence of a typical scoliotic evolution pattern and suggest that scoliotic evolution is quite variable and patient specific.
Scoliosis, 2008
Background: Hueter-Volkmann's law regarding growth modulation suggests that increased pressure on the end plate of bone retards the growth (Hueter) and conversely, reduced pressure accelerates the growth (Volkmann). Literature described the same principle in Rat-tail model. Human spine and its deformity i.e. scoliosis has also same kind of pattern during the growth period which causes wedging in disc or vertebral body. Methods: This cross sectional study in 150 patients of adolescent idiopathic scoliosis was done to evaluate vertebral body and disc wedging in scoliosis and to compare the extent of differential wedging of body and disc, in thoracic and lumbar area. We measured wedging of vertebral bodies and discs, along with two adjacent vertebrae and disc, above and below the apex and evaluated them according to severity of curve (curve < 30° and curve > 30°) to find the relationship of vertebral body or disc wedging with scoliosis in thoracic and lumbar spine. We also compared the wedging and rotations of vertebrae. Results: In both thoracic and lumbar curves, we found that greater the degree of scoliosis, greater the wedging in both disc and body and the degree of wedging was more at apex supporting the theory of growth retardation in stress concentration area. However, the degree of wedging in vertebral body is more than the disc in thoracic spine while the wedging was more in disc than body in lumbar spine. On comparing the wedging with the rotation, we did not find any significant relationship suggesting that it has no relation with rotation. Conclusion: From our study, we can conclude that wedging in disc and body are increasing with progression on scoliosis and maximum at apex; however there is differential wedging of body and disc, in thoracic and lumbar area, that is vertebral body wedging is more profound in thoracic area while disc wedging is more profound in lumbar area which possibly form 'vicious cycle' by asymmetric loading to spine for the progression of curve.
The Spine Journal, 2018
Background Context. One of the characteristics of reported observations in adolescent idiopathic scoliosis (AIS) is that the thoracic spine is longer anteriorly than posteriorly, more pronounced around the apex than the transitional zones. This reversal of the normal kyphotic anatomy of the thoracic spine is related to questions of etiopathogenesis of AIS. The changes in the anatomy of the anterior column have been described rather in detail, however, the role of the posterior spinal column and the laminae has so far not been elucidated. If the posterior column exhibits a longitudinal growth disturbance, it could act as a tether, leading to a more or less normal anterior column with a deformed and shorter posterior aspect of the spine. So far, it has remained unclear whether this anterior-posterior length discrepancy is the result of relative anterior lengthening or relative posterior shortening, and which tissues (bone, disc, intervertebral soft tissue) are involved. Purpose. To compare the discrepancy of the anterior-posterior length of the spinal column in the 'true' midsagittal plane of each vertebra in idiopathic scoliosis patients versus controls, using three-dimensional CT scans. Study Design/Setting. Cross-sectional. Patient Sample. CT scans of 80 moderate to severe AIS patients (Cobb angle: 46-109°) prior to scoliosis navigation surgery and 30 non-scoliotic age-matched controls. Outcome Measures. The height of the osseous and non-osseous structures from anterior to posterior in the 'true' midsagittal plane: the anterior side of the vertebral body and disc, the posterior side of the vertebral body and disc, the lamina and interlaminar space and the spinous process and interspinous space, as well as the height ratios between the anterior column and posterior structures of the primary thoracic and lumbar AIS curves and corresponding levels in non-scoliotic controls. Methods. Semi-automatic software was used to reconstruct and measure the parameters in the true midsagittal plane of each vertebra and intervertebral structure, that are rotated and tilted in a different way. Results. In AIS, the anterior height of the thoracic curve was 3.6±2.8% longer as compared to the posterior height, 2.0±6.1% longer than the length along the laminae and 8.7±7.1% longer than the length along the spinous processes and this differed significantly from controls (-2.7±2.4%,-7.4±5.2% and +0.7±7.8%; p<0.001). The absolute height of the osseous parts did not differ significantly between AIS and controls in the midsagittal plane. In contrast, the intervertebral structures contributed significantly to the observed length discrepancies. In absolute lengths, the anterior side of the disc of the thoracic curve was higher in AIS (5.4±0.8 mm) than controls (4.8±1.0 mm; p<0.001), whereas the interspinous space was smaller in AIS (12.3±1.4 mm versus 14.0±1.6 mm; p<0.001). Conclusions. Based on this in vivo analysis, the true three-dimensional anterior-posterior length discrepancy of AIS curves was found to occur through both anterior column lengthening as well as posterior column shortening, with the facet joints functioning as the fulcrum. The vertebrae contribute partly to the anterior-posterior length discrepancy accompanied by more significant and possibly secondary increased anterior intervertebral discs height.
2021
Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional (3D) spinal deformity affecting 0.47-5.2% of the population and is up to ten times more common in females than males. Although there are multiple types of scoliosis, AIS is the most prevalent type, accounting for 80% of cases. With increased severity of the scoliotic curve, some patients will require treatment either with bracing or spinal instrumentation, with the latter being associated with significant risks and reduced spinal flexibility. For this reason, early diagnosis and sound understanding of the 3D pathoanatomy associated with AIS, is paramount in optimal treatment outcomes. Few studies have analysed multi-dimensional anatomical changes in the vertebrae in a large cohort and prospectively over a period of time. To understand how the sagittal and axial plane deformity changes with curve progression, this study used a sequential series of magnetic resonance images (MRI) for both AIS participants and non-scoliotic controls. Wedge angles, vertebral body (VB) heights, axial vertebral rotation (AVR) and thoracic kyphosis were compared at three time-points during adolescent growth. This study found a significant hypokyphosis already evident at MRI scan 1 in the AIS cohort, and subsequent reduction or very modest increase in kyphosis over the subsequent MRI scans, when compared to non-scoliotic control participants. Further contributing factors to the scoliotic deformity include a failure of progression of an anterior wedge of VBs and a relative slower growth rate of the posterior VB height. There was an observed reduction in axial vertebral rotation (AVR) three levels above and below the apex of the curve which may indicate the transition to a compensatory curve in the scoliotic deformity. Intravertebral rotation (IVR) had a greater progressive change at periapical levels when compared to the apex, which may contribute to the non-uniform de-rotation achieved following instrumented fusion surgery. Overall this study contributes to the understanding of spinal deformity progression in AIS patients, which will hopefully aid in therapeutic planning and optimise treatment outcomes.
Journal of Clinical Medicine, 2021
Introduction and aim of the study: We aim to determine whether the changes in the spine in scoliogenesis of idiopathic scoliosis (IS), are primary/inherent or secondary. There is limited information on this issue in the literature. We studied the sagittal profile of the spine in IS using surface topography. Material and methods: After approval of the ethics committee of the hospital, we studied 45 children, 4 boys and 41 girls, with an average age of 12.5 years (range 7.5–16.4 years), referred to the scoliosis clinic by our school screening program. These children were divided in two groups: A and B. Group A included 17 children with IS, 15 girls and 2 boys. All of them had a trunk asymmetry, measured with a scoliometer, greater than or equal to 5 degrees. Group B, (control group) included 26 children, 15 girls and 11 boys, with no trunk asymmetry and scoliometer measurement less than 2 degrees. The height and weight of children were measured. The Prujis scoliometer was used in stan...
BackgroundVertebral and intervertebral disc (IVD) wedging are often seen in patients with adolescent idiopathic scoliosis (AIS). However, the relationship between wedging and curve progression, and the change of wedging before bracing to final weaning is unknown. The aim of this study was to investigate the pattern and sequence of vertebral and IVD wedging development, and to determine the relationship between the change of wedging and curve progression in AIS during growth.MethodsThis was a prospective study of 32 AIS females with right-sided thoracic curves and/or left-sided lumbar curves who completed brace treatment. They were classified into progression and non-progression groups. Vertebral and IVD wedging were calculated for each spinal segment. The wedging pattern was first identified and then used to determine the sequence of wedging development. Percentage change in the sum of wedging during growth was calculated and compared.ResultsThe sum of vertebral wedging for both gro...
2018
Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional (3D) spinal deformity affecting 0.47-5.2% of the population and is up to ten times more common in females than males. Although there are multiple types of scoliosis, AIS is the most prevalent type, accounting for 80% of cases. With increased severity of the scoliotic curve, some patients will require treatment either with bracing or spinal instrumentation, with the latter being associated with significant risks and reduced spinal flexibility. For this reason, early diagnosis and sound understanding of the 3D pathoanatomy associated with AIS, is paramount in optimal treatment outcomes. Few studies have analysed multi-dimensional anatomical changes in the vertebrae in a large cohort and prospectively over a period of time. To understand how the sagittal and axial plane deformity changes with curve progression, this study used a sequential series of magnetic resonance images (MRI) for both AIS participants and non-scoliotic controls. Wedge angles, vertebral body (VB) heights, axial vertebral rotation (AVR) and thoracic kyphosis were compared at three time-points during adolescent growth. This study found a significant hypokyphosis already evident at MRI scan 1 in the AIS cohort, and subsequent reduction or very modest increase in kyphosis over the subsequent MRI scans, when compared to non-scoliotic control participants. Further contributing factors to the scoliotic deformity include a failure of progression of an anterior wedge of VBs and a relative slower growth rate of the posterior VB height. There was an observed reduction in axial vertebral rotation (AVR) three levels above and below the apex of the curve which may indicate the transition to a compensatory curve in the scoliotic deformity. Intravertebral rotation (IVR) had a greater progressive change at periapical levels when compared to the apex, which may contribute to the non-uniform de-rotation achieved following instrumented fusion surgery. Overall this study contributes to the understanding of spinal deformity progression in AIS patients, which will hopefully aid in therapeutic planning and optimise treatment outcomes.
Spine deformity, 2017
The aim of this study was to measure contributions of individual vertebra and disc wedging to coronal Cobb angle in the growing scoliotic spine using sequential magnetic resonance imaging (MRI). Clinically, the Cobb angle measures the overall curve in the coronal plane but does not measure individual vertebra and disc wedging. It was hypothesized that patients whose deformity progresses will have different patterns of coronal wedging in vertebrae and discs to those of patients whose deformities remain stable. A group of adolescent idiopathic scoliosis (AIS) patients each received two to four MRI scans (spaced 3-12 months apart). The coronal plane wedge angles of each vertebra and disc in the major curve were measured for each scan, and the proportions and patterns of wedging in vertebrae and discs were analyzed for subgroups of patients whose spinal deformity did and did not progress during the study period. Sixteen patients were included in the study; the mean patient age was 12.9 ...
Morphological Analysis of Thoracolumbar Spine Pedicles in Adolescent Idiopathic Scoliosis
Journal of Turkish Spinal Surgery
Objective: Adolescent idiopathic scoliosis (AIS) is a three-dimensional spinal deformity, and pedicle morphology can change on the concave and convex sides of the curvature. This study aimed to evaluate the pedicle morphology of the thoracic and lumbar vertebrae in AIS via computed tomography (CT). Materials and Methods: Patients diagnosed with AIS between 2019 and 2021 were identified by scanning the Picture Archiving and Communication System. Patients with a scoliosis radiograph and a Cobb angle of 40º or more were included in the study. The pedicle length (PL), axial pedicle angle (APA), endosteal pedicle width (EPW), and cord length (CL) were measured from the T1 to L5 vertebrae from the CT sections of the patients. The Cobb angle, apical vertebral translation distance, and vertebral rotations were measured using standing AP and lateral radiographs. Results: The mean age of the 30 patients was 16.37±3.0 and 93.3% were females. The mean main-thoracic Cobb angle was 47.87º±7.99º. There was a significant, negatively weak relationship between the Cobb angle and T5 and T6 left PL (r=-0.485 and r=-0.371, respectively), a moderately negative relationship between T7 and L3 left PL (r=0.506 and r=-0.508, respectively). There was no significant correlation between the Cobb angle and endosteal pedicle values (p>0.05). While the correlation between the vertebral rotation and the right endosteal pedicle was moderate at T4, a significant but low correlation was found for T3, T5, T6, T7, and T9 (p<0.05). Conclusion: The EPW was shorter and the CL was longer on the concave side of the vertebrae in the apical region of the AIS deformity. It is essential to know the pedicle morphology order to avoid complications, especially in pedicle screw implantation in the apical concave region.