Correlation of vertebral strength topography with 3-dimensional computed tomographic structure

Area of Science:

• Biomechanics
• Orthopedic research
• Medical imaging

Background:

• In vivo evaluation of vertebral bone mechanical properties is limited.
• Vertebral strength topography is hypothesized to depend on local 3D bone structure.
• Quantitative computed tomography (CT) may allow for discrete site evaluation.

Purpose of the Study:

• To test if lumbar vertebral stiffness and strength depend on 3D bone structure and density.
• To determine if models based on quantitative CT can evaluate these properties.
• To investigate the relationship between bone characteristics and mechanical properties.

Main Methods:

• Biomechanical and radiographical study of 48 human lumbar vertebrae from 14 cadavers.
• Indentation tests measured stiffness and strength at 11 discrete endplate sites.
• Micro-CT and conventional CT (con-CT) analyzed bone characteristics; predictive models were created.

Main Results:

• Local stiffness and strength were highly variable.
• Endplate thickness, density, adjacent trabecular bone density, endplate defects, and age predicted local properties.
• Regression models showed strong correlation with stiffness (r2=0.82) and strength (r2=0.74).

Conclusions:

• Lumbar vertebral stiffness and strength depend on superficial bone structure and density.
• Quantitative analysis of micro-CT and con-CT images can evaluate these properties.
• This approach may improve clinical assessment of vertebral bone.