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.
Skip Nav Destination
e-mail: carl-eric.aubin@polymtl.ca
Article navigation
December 2002
Technical Briefs
Simulation of Progressive Deformities in Adolescent Idiopathic Scoliosis Using a Biomechanical Model Integrating Vertebral Growth Modulation
I. Villemure,
I. Villemure
Research Center, Sainte-Justine Hospital 3175, Cote Sainte-Catherine Road Montreal (Quebec) H3T 1C5 Canada
University of Montreal Biomedical Engineering Institute P.O. Box 6128, Station “Centre-ville” Montreal (Quebec) H3C 3J7 Canada
Search for other works by this author on:
C. E´. Aubina,
e-mail: carl-eric.aubin@polymtl.ca
C. E´. Aubina
Research Center, Sainte-Justine Hospital 3175, Cote Sainte-Catherine Road Montreal (Quebec) H3T 1C5 Canada
Ecole Polytechnique de Montreal Mechanical Engineering Department P.O. Box 6079, Station “Centre-ville” Montreal (Quebec) H3C 3A7 Canada
Search for other works by this author on:
J. Dansereau,
J. Dansereau
Research Center, Sainte-Justine Hospital 3175, Cote Sainte-Catherine Road Montreal (Quebec) H3T 1C5 Canada
Ecole Polytechnique de Montreal Mechanical Engineering Department P.O. Box 6079, Station “Centre-ville” Montreal (Quebec) H3C 3A7 Canada
Search for other works by this author on:
H. Labelle
H. Labelle
Research Center, Sainte-Justine Hospital 3175, Cote Sainte-Catherine Road Montreal (Quebec) H3T 1C5 Canada
University of Montreal Biomedical Engineering Institute P.O. Box 6128, Station “Centre-ville” Montreal (Quebec) H3C 3J7 Canada
Search for other works by this author on:
I. Villemure
Research Center, Sainte-Justine Hospital 3175, Cote Sainte-Catherine Road Montreal (Quebec) H3T 1C5 Canada
University of Montreal Biomedical Engineering Institute P.O. Box 6128, Station “Centre-ville” Montreal (Quebec) H3C 3J7 Canada
C. E´. Aubina
Research Center, Sainte-Justine Hospital 3175, Cote Sainte-Catherine Road Montreal (Quebec) H3T 1C5 Canada
Ecole Polytechnique de Montreal Mechanical Engineering Department P.O. Box 6079, Station “Centre-ville” Montreal (Quebec) H3C 3A7 Canada
e-mail: carl-eric.aubin@polymtl.ca
J. Dansereau
Research Center, Sainte-Justine Hospital 3175, Cote Sainte-Catherine Road Montreal (Quebec) H3T 1C5 Canada
Ecole Polytechnique de Montreal Mechanical Engineering Department P.O. Box 6079, Station “Centre-ville” Montreal (Quebec) H3C 3A7 Canada
H. Labelle
Research Center, Sainte-Justine Hospital 3175, Cote Sainte-Catherine Road Montreal (Quebec) H3T 1C5 Canada
University of Montreal Biomedical Engineering Institute P.O. Box 6128, Station “Centre-ville” Montreal (Quebec) H3C 3J7 Canada
Contributed by the Bioengineering Division for publication in the JOURNAL OF BIOMECHANICAL ENGINEERING. Manuscript received Aug. 2000; revised manuscript received June 2002. Associate Editor: V. K. Goel.
J Biomech Eng. Dec 2002, 124(6): 784-790 (7 pages)
Published Online: December 27, 2002
Article history
Received:
August 1, 2000
Revised:
June 1, 2002
Online:
December 27, 2002
Citation
Villemure, I., Aubina, C. E., Dansereau , J., and Labelle, H. (December 27, 2002). "Simulation of Progressive Deformities in Adolescent Idiopathic Scoliosis Using a Biomechanical Model Integrating Vertebral Growth Modulation." ASME. J Biomech Eng. December 2002; 124(6): 784–790. https://doi.org/10.1115/1.1516198
Download citation file:
Get Email Alerts
Changes in Dynamic Mean Ankle Moment Arm in Unimpaired Walking Across Speeds, Ramps, and Stairs
J Biomech Eng (September 2024)
Related Articles
Application of the Finite Element Technique in the Design and Evaluation of the Artificial Facets for the Lumbar Spine
J. Med. Devices (June,2007)
Novel Design for Jaw-Thrust and Head Immobilization Device and Its Successful Testing Using Human Simulator
J. Med. Devices (June,2010)
Development and Validation of A C0–C7 FE Complex for Biomechanical Study
J Biomech Eng (October,2005)
Related Proceedings Papers
Related Chapters
Vibration Analysis of the Seated Human Body in Vertical Direction
International Conference on Computer Technology and Development, 3rd (ICCTD 2011)
Testing of Human Cadaveric Functional Spinal Units to the ASTM Draft Standard, “Standard Test Methods for Static and Dynamic Characterization of Spinal Artificial Discs”
Spinal Implants: Are We Evaluating Them Appropriately?
Simulation of Thai Population Migration for Epidemiological Study
International Conference on Computer and Computer Intelligence (ICCCI 2011)