Maximum forces applied to the orbital floor after fractures.

Area of Science:

• Biomedical Engineering
• Trauma Surgery
• Materials Science

Background:

• Orbital trauma can lead to severe injuries, including orbital floor defects.
• Accurate measurement of forces on intraorbital tissues is crucial for selecting appropriate reconstruction materials.
• Understanding the biomechanics of orbital floor displacement is essential for predicting surgical outcomes.

Purpose of the Study:

• To measure the force and displacement of detached intraorbital tissue in a worst-case orbital trauma scenario.
• To determine the maximum load on orbital tissues to guide the selection of reconstruction materials.
• To predict the necessary strength of materials for orbital floor reconstruction.

Main Methods:

• Six fresh-frozen human heads were used to create orbital floor defects via blunt impact (3.0 J).
• Orbital floor defect sizes and tissue displacements were measured after Le Fort I osteotomy.
• Forces and displacements were measured on repositioned intraorbital tissue.

Main Results:

• Mean orbital floor defect sizes ranged from 208.3 mm² (globe impacts) to 221.8 mm² (infraorbital impacts).
• Initial intraorbital tissue displacement averaged 5.6 mm (globe impacts) and 2.8 mm (infraorbital impacts).
• Post-repositioning displacements were minimal (0.8 mm and 1.1 mm), with measured forces around 0.11 N.

Conclusions:

• The maximum forces exerted on completely detached orbital tissue are minimal, approximately 0.11 N.
• Collagen membranes are suggested as suitable reconstruction materials for medium-sized orbital floor defects.
• These findings aid in the selection of effective and safe materials for orbital reconstruction after trauma.