Module 5 - Head and Neck

Craniomaxillofacial Trauma

Internal Orbit and "Blow out" Fractures

A. Internal Orbit Fractures

• Confined to the orbital floor and located medial to the groove for the infraorbital nerve
• May involve floor, medial wall, lateral wall and roof in decreasing order
• Soft tissue herniated into the maxillary and/or ethmoid sinus(es)
• Fractures may occur with or without orbital rim fracturing
• Herniated tissue can prevent movement of the extra-ocular muscles (diplopia)
• Most commonly involved muscle is the inferior rectus

 

B. "Blow-out Fractures"

• Mechanism - transmitted force through the orbital rim
• Signs & Symptoms
• Classical history
• Diplopia on extremes of gaze, positive forced duction test
• Limited range of EOM movement
• V2 numbness
• Incidence of globe injury is high
• Must rule out globe rupture, hyphema, retinal detachment
• Enophthalmos (sunken globe)

 

C. Treatment of Blow-out Fractures

Absolute indications for surgery:

• Positive forced duction test
• Large defect on CT scan with diplopia and enophthalmos

 

When unsure:

• Small defect, diplopia on extreme of lateral gaze
• Observe for 7-10 days; if persistent, operate

 

Author: Dr. R. Bendor-Samuel