F.E.M. Stress-Investigation of Scolios Apex

Area of Science:

• Biomedical Engineering
• Computational Mechanics
• Radiology

Background:

• Scoliosis involves vertebral wedging and tilting, influencing spinal stress distribution.
• Stress concentration is expected at the apex of the curvature.

Purpose of the Study:

• To develop an algorithm for generating artificial geometric models of the vertebral column from DICOM image stacks.
• To create simplified models focusing on vertebral wedge properties and relative tilting for stress analysis.

Main Methods:

• Parameter extraction from DICOM (Digital Imaging and Communications in Medicine) image stacks.
• Finite Element Method (FEM) modeling using Matlab and Comsol.
• Construction of models for five patients with thoracic idiopathic scoliosis.

Main Results:

• A response variable based on distortion energy was calculated for various load states.
• Pairwise t-tests indicated the response variable is sensitive to transversal stresses.
• No significant difference was found between isotropic and orthotropic material modeling (p≈0.084).

Conclusions:

• A procedure for constructing artificial geometric models from CT DICOM stacks for semi-global stress analysis is described.
• The method is suitable for analyzing wedge properties and tilting, but not surface irregularities.
• Preliminary findings suggest a correlation between a specific load state and apex distortion energy, requiring further validation with larger patient cohorts.