Simulation of vertebral trabecular bone loss using voxel finite element analysis

Area of Science:

• Biomechanical engineering
• Orthopedic research
• Computational modeling

Background:

• Trabecular bone loss in vertebrae is characterized by thinning and perforation of horizontal trabeculae and complete loss of vertical trabeculae.
• This bone loss leads to reduced mechanical properties of the vertebral trabecular core.

Purpose of the Study:

• To model vertebral trabecular bone loss using a voxel-based finite element program.
• To investigate the roles of strain adaptive resorption and microdamage mechanisms in bone loss.

Main Methods:

• Utilized a voxel-based finite element program to simulate bone loss in three human vertebral trabecular bone specimens.
• Performed three sets of analyses: strain adaptive resorption only, strain adaptive plus microdamage resorption, and modified microdamage resorption with increased damage threshold.

Main Results:

• Strain adaptive resorption alone did not fully explain observed mechanical property deterioration.
• Including microdamage resorption led to vertical trabeculae perforation and vertebral network collapse under compression.
• Adjusting the damage threshold simulated architectures matching experimental apparent modulus values.

Conclusions:

• Strain adaptive remodeling alone is insufficient to account for experimental observations of vertebral bone mechanical property decline.
• Horizontal trabeculae are likely lost via strain adaptive resorption.
• Vertical trabeculae may be lost through microdamage-induced perforation followed by strain adaptive resorption.