Dynamic three-dimensional finite element analysis of orbital trauma

Area of Science:

• Biomechanics
• Computational modeling
• Ophthalmology

Background:

• Orbital trauma mechanisms, including buckling and hydraulic theories, are crucial for understanding injury.
• Accurate digital models of the orbital cavity are essential for simulating trauma.
• The role of soft tissues in mitigating orbital impact forces requires further elucidation.

Purpose of the Study:

• To perform a dynamic finite element analysis of orbital trauma mechanisms.
• To investigate stress distribution in orbital walls under different impact scenarios.
• To assess the influence of soft tissue on impact energy absorption.

Main Methods:

• Creation of a detailed finite element model of the orbital cavity using patient-specific imaging data.
• Simulation of two impact scenarios: hydraulic (eyeball impact) and buckling (infraorbital rim impact).
• Calculation of first principal stress to map stress distribution and identify high-stress areas.

Main Results:

• The finite element model comprised over 900,000 elements, with simulation times of 4.8 ms (hydraulic) and 0.6 ms (buckling).
• Hydraulic mechanism resulted in high stress on the medial wall (99.08 mm²), while buckling affected the orbital floor (378.70 mm²).
• Orbital soft tissues notably absorbed impact energy, especially in the hydraulic mechanism.

Conclusions:

• A complete orbital model was successfully constructed using advanced segmentation techniques.
• Simulated results align with established experimental findings for both trauma mechanisms.
• Soft tissue plays a critical protective role by absorbing impact energy, impacting orbital pathophysiology.