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

PLoS ONE ◽  
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.

Evaluation of body geometry and symmetry for adolescent idiopathic scoliosis with 3D body scanning system

2017 ◽  
Vol 21 (4) ◽  
pp. 276-292
Author(s):  
Lu Lu ◽  
Kit-Lun Yick ◽  
Sun Pui Ng ◽  
Joanne Yip ◽  
Chi Yung Tse
Keyword(s):  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Three Dimensional ◽  
The Body ◽  
Scanning System ◽  
X Rays ◽  
Cross Sectional ◽  
Content Type ◽  
Body Scanning ◽  
The Cross

Purpose The purpose of this paper is to quantitatively assess the three-dimensional (3D) geometry and symmetry of the torso for spinal deformity and the use of orthotic bracewear by using non-invasive 3D body scanning technology. Design/methodology/approach In pursuing greater accuracy of body anthropometric measurements to improve the fit and design of apparel, 3D body scanning technology and image analysis provide many more advantages over the traditional manual methods that use contact measurements. To measure the changes in the torso geometry and profile symmetry of patients with adolescent idiopathic scoliosis, five individuals are recruited to undergo body scanning both with and without wearing a rigid brace during a period of six months. The cross-sectional areas and profiles of the reconstructed 3D torso models are examined to evaluate the level of body symmetry. Findings Significant changes in the cross-sectional profile are found amongst four of the patients over the different visits for measurements (p < 0.05), which are consistent with the X-rays results. The 3D body scanning system can reliably evaluate changes in the body geometry of patients with scoliosis. Nevertheless, improvements in the symmetry of the torso are found to be somewhat inconsistent among the patients and across different visits. Originality/value This pilot study demonstrates a practical and safe means to measure and analyse the torso geometry and symmetry so as to allow for more frequent evaluations, which would result in effective and optimal treatment of spinal deformation.

scholarly journals Determination of three-dimensional corrective force in adolescent idiopathic scoliosis and biomechanical finite element analysis

2019 ◽  
Author(s):  
Tianmin Guan ◽  
Yu-fang Zhang
Keyword(s):  
Finite Element ◽  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Objective Function ◽  
Soft Tissues ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Maximum Displacement ◽  
Computed Tomography Images ◽  
Three Dimensional Space

Abstract Background: Adolescent idiopathic scoliosis is a complex three-dimensional deformity of spine and soft tissues. It is usually treated with spinal brace if Cobb angle is less than 40°. To date, displacement and rotation of human vertebrae and ribs in three-dimensional space have not been fully considered in treatment of scoliosis. Three dimensional corrective forces in treatment of scoliosis are still unclear and very less attention has paid on it.Methods: An objective function of corrective force in three-dimensional space is defined. Computed tomography images were used to reconstruct three dimensional model of scoliotic trunk. Computer aided engineering software Abaqus was used to establish finite element model of deformed spine and its biomechanical characteristics were analyzed. By adjusting magnitude and position of corrective forces, objective function is minimized to achieve best orthopedic effect. The proposed corrective conditions were divided into three groups: 1. thoracic deformity; 2. lumbar deformity; 3. both thoracic and lumbar deformities were considered.Results: In all three cases, the objective function was reduced by 58%, 52%, and 63%, respectively. The best correction force point is located on convex side of maximum displacement of vertebral body.Conclusions: Using minimum objective function method, spinal deformity in three-dimensional space can be sufficiently reduced. This study provides scientific basis for design of a new corrective brace for treatment of scoliosis.

scholarly journals Prediction of Scoliosis Curve Correction Using Apical Fulcrum Bending Radiographs in Adolescent Idiopathic Scoliosis (AIS)

2021 ◽  
Keyword(s):  
Surgical Treatment ◽  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Age Determination ◽  
Three Dimensional ◽  
University Hospital ◽  
Spinal Curvatures ◽  
Scoliotic Deformity ◽  
Cobb’S Angle ◽  
Selection Of

Background: Scoliosis is defined as a three-dimensional deformity of spine. Surgical treatment is indicated for curves equal to/or more than 40 degrees in magnitude. Curve flexibility is determined preoperatively through bending films, which help in the selection of fusion levels. Surgical treatment for fully-grown spine is a spinal fusion use to inhibit the progress of deformity which further helps in balancing of both sagittal and coronal planes. Therefore, this study aimed to find out the association between predicted via bending films after correction and final surgical correction of skeletally mature patients with Adolescent Idiopathic Scoliosis (AIS). Methods: Thirty-three patients with Adolescent Idiopathic Scoliosis (AIS) were recruited for the study. Those patients were operated at Dr. Ziauddin University Hospital, Karachi from June 2016 to June 2020. Using Pre- and post-operative radiographs of the spine, Cobb values were used to calculate the percentage of correction achieved. Percentage correction (surgical) was then compared to correction possible (predicted) to find association via an independent t-test with p<0.05 considered as statistically significant. Results: Out of total 33 patients, 24 (72.7%) were females and 9 (27.2%) were males. The mean age of the patients was 17.2±3.0 years. Using bending films, correction of the scoliotic deformity was predicted through measured angles with 78±18°. The corrections’ difference was 84.5±11°. This difference was found to be statistically insignificant (p=0.0769) which showed no difference in predicted and actual correction achieved. Conclusion: In skeletally mature patients with AIS, bending films have been shown to accurately predict the amount of postoperative correction of Cobb’s angle which is possible. Keywords: Age Determination by Skeleton; Scoliosis; X-Ray Film; Spinal Curvatures.

Simulation of Progressive Deformities in Adolescent Idiopathic Scoliosis Using a Biomechanical Model Integrating Vertebral Growth Modulation

2002 ◽  
Vol 124 (6) ◽  
pp. 784-790 ◽  
Author(s):  
I. Villemure ◽  
C. E´. Aubina ◽  
J. Dansereau ◽  
H. Labelle
Keyword(s):  
Finite Element ◽  
Adolescent Idiopathic Scoliosis ◽  
Idiopathic Scoliosis ◽  
Biomechanical Model ◽  
Element Model ◽  
Axial Rotation ◽  
Growth Cycle ◽  
Growth Modulation ◽  
Growth Plates ◽  
Vertebral Growth

While the etiology and pathogenesis of adolescent idiopathic scoliosis are still not well understood, it is generally recognized that it progresses within a biomechanical process involving asymmetrical loading of the spine and vertebral growth modulation. This study intends to develop a finite element model incorporating vertebral growth and growth modulation in order to represent the progression of scoliotic deformities. The biomechanical model was based on experimental and clinical observations, and was formulated with variables integrating a biomechanical stimulus of growth modulation along directions perpendicular (x) and parallel (y, z) to the growth plates, a sensitivity factor β to that stimulus and time. It was integrated into a finite element model of the thoracic and lumbar spine, which was personalized to the geometry of a female subject without spinal deformity. An imbalance of 2 mm in the right direction at the 8th thoracic vertebra was imposed and two simulations were performed: one with only growth modulation perpendicular to growth plates (Sim1), and the other one with additional components in the transverse plane (Sim2). Semi-quantitative characterization of the scoliotic deformities at each growth cycle was made using regional scoliotic descriptors (thoracic Cobb angle and kyphosis) and local scoliotic descriptors (wedging angle and axial rotation of the thoracic apical vertebra). In all simulations, spinal profiles corresponded to clinically observable configurations. The Cobb angle increased non-linearly from 0.3° to 34° (Sim1) and 20° (Sim2) from the first to last growth cycle, adequately reproducing the amplifying thoracic scoliotic curve. The sagittal thoracic profile (kyphosis) remained quite constant. Similarly to clinical and experimental observations, vertebral wedging angle of the thoracic apex progressed from 2.6° to 10.7° (Sim1) and 7.8° (Sim2) with curve progression. Concomitantly, vertebral rotation of the thoracic apex increased of 10° (Sim1) and 6° (Sim2) clockwise, adequately reproducing the evolution of axial rotation reported in several studies. Similar trends but of lesser magnitude (Sim2) suggests that growth modulation parallel to growth plates tend to counteract the growth modulation effects in longitudinal direction. Overall, the developed model adequately represents the self-sustaining progression of vertebral and spinal scoliotic deformities. This study demonstrates the feasibility of the modeling approach, and compared to other biomechanical studies of scoliosis it achieves a more complete representation of the scoliotic spine.

scholarly journals Evaluation of a Patient-Specific Finite-Element Model to Simulate Conservative Treatment in Adolescent Idiopathic Scoliosis

2015 ◽  
Vol 3 (1) ◽  
pp. 4-11 ◽  
Author(s):  
Claudio Vergari ◽  
Gwenael Ribes ◽  
Benjamin Aubert ◽  
Clayton Adam ◽  
Lotfi Miladi ◽  
...  
Keyword(s):  
Finite Element ◽  
Adolescent Idiopathic Scoliosis ◽  
Conservative Treatment ◽  
Idiopathic Scoliosis ◽  
Finite Element Model ◽  
Element Model ◽  
Patient Specific
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