Mapping the Risk of Fracture of the Tibia From Penetrating Fragments

Area of Science:

• Biomechanics
• Trauma research
• Forensic science

Background:

• Penetrating injuries from explosive devices frequently affect extremities, particularly the leg.
• These injuries pose risks of infection, delayed healing, and potential amputation.

Purpose of the Study:

• To quantify fracture risk to different aspects of the tibia (anteromedial, posterior, lateral) from metal fragment-simulating projectiles (FSPs).
• To develop fracture-risk curves for the human tibia based on ovine tibia models.

Main Methods:

• Utilized a gas gun system to launch 0.78-g cylindrical FSPs at an ovine tibia model.
• Scaled results to human tibia using cortical thickness ratio and considering soft tissue depth.
• Applied the modified Winquist-Hansen classification for fracture types (EF1+ to EF4+).

Main Results:

• The lateral cortex of the tibia demonstrated the highest susceptibility to fracture.
• Impact velocities for 50% risk of EF1+, EF2+, EF3+, and EF4+ fractures were determined as 174, 190, 212, and 282 m/s, respectively.

Conclusions:

• The lateral tibia is the most vulnerable aspect to projectile-induced fractures.
• Findings will enhance the accuracy of predictive models for projectile penetration injuries.