Development of a Template Finite Element Model of Congenital Early Onset Scoliosis
Tuesday, June 2, 2026
3:30 PM-5:30 PM
BIOMED Master's Thesis Defense
Title:
Development of a Template Finite Element Model of Congenital Early Onset Scoliosis to Assess Spinal Kinematics and Growth-Driven Deformity Progression
Speaker:
Shreya Juvvadi, Master's Candidate
School of Biomedical Engineering, Science and Health Systems
Drexel University
Advisor:
Sriram Balasubramanian, PhD
Professor
School of Biomedical Engineering, Science and Health Systems
Drexel University
Details:
Early Onset Scoliosis (EOS) is a progressive spine and thoracic cage deformity diagnosed in children under the age of 10 years, defined by a Cobb angle of ≥ 10º. The thoracospinal deformity is marked by thoracic insufficiency syndrome (TIS), which is the inability of the thorax to support normal respiration and lung growth. Congenital EOS is the less common etiology that is diagnosed shortly after birth but is most complex and poses difficulty for surgeons to treat due to abnormal vertebral and rib development. Finite element (FE) modeling has been used previously to study spine growth and effectiveness of surgical interventions in adolescent idiopathic scoliosis (AIS); however, these models are not directly applicable to congenital EOS due to differences in anatomy, deformity characteristics, patient age range, and growth dynamics. Currently, congenital EOS FE models do not capture patient-specific (PS) anatomical variations, including abnormal rib and vertebral morphology and do not incorporate region-specific vertebral body growth. Therefore, the objective of the current study is to develop a high-quality, hexahedral, congenital EOS osteo-ligamentous FE model of the T1-L5 spine with intervertebral discs (IVDs), ribcage, sternum, and pelvis to enable better evaluation of altered spine kinematics and deformity progression resulting from growth.
Specific aim 1 was to develop a congenital EOS osteo-ligamentous FE model that incorporates the T1-L5 spine with IVDs, ribcage, sternum, and pelvis and simulate range of motion (ROM) in flexion-extension, lateral bending, and axial rotation. Chest and abdominal supine CT scans of a four-year-old female congenital EOS patient were digitally segmented and reconstructed. The0020se reconstructed geometries were used to create high quality hexahedral meshes of the anatomy. The final congenital EOS FE model consisted of 142,289 elements that were 98% hexahedral. The FE model met the acceptance criteria for mesh quality; the Jacobian is greater than 0.5 in 90.3% of elements, warpage is less than 50 in 97% of elements, skewness is less than 60 in 94% of elements, and aspect ratio is less than 5.0 in 93% of elements. This completed FE model was then used to simulate ROM in flexion-extension, lateral bending, and axial rotation by applying a 1.2 Nm moment on the T1 vertebra while the pelvis was held fixed. The model predicted T1-T12 angular displacement of 33 degrees flexion, 31 degrees extension, 28-36 degrees lateral bending, and 8-29 degrees axial rotation. Thoracic and lumbar Cobb displacements of 21 and 8 degrees were recorded, respectively for convex side bending. A sensitivity analysis varying IVD elastic modulus ± 25% from baseline (16 MPa) confirmed that curve flexibility was predominantly governed by structural spine deformity rather than IVD material properties.
Specific aim 2 was to simulate one year of growth in the congenital EOS template FE model by incorporating region-specific and asymmetric stress-based vertebral growth to evaluate spinal deformity progression in congenital EOS. Growth was modeled using previously created thermal expansion methods, with vertebral body strain rate updates at 3,6, and 9 months to replicate growth modulation. The model demonstrated curve progression, with thoracic (T1-T12) and lumbar (L1-L3) Cobb angles increasing 6 and 8 degrees per year, respectively. Spinal height (T1-L5) increased by 8 mm/year, falling below normative growth values of 1.1-1.2 cm/year.
The final congenital EOS template FE model simulated altered ROM and deformity progression with growth. This model will serve as a template for future generations of patient-specific congenital EOS FE models. Such models hold promise as a viable tool to predict surgical outcomes and optimize correction strategies for patients with congenital EOS.
Contact Information
Natalia Broz
njb33@drexel.edu