Blowout Fracture of the Orbit

 

  • General Considerations
    • Isolated fractures, most commonly of the orbital floor
    • The cause is sudden, direct, blunt trauma in the form of a blow to the orbit with increase in intraorbital pressure
    • The orbital rim is relatively strong so force is transmitted to the weakest parts of the orbit which “blow-out”
      • Orbital floor which is the superior boundary of the maxillary sinus, or
      • Medial wall (the thin lamina papyracea) which is the lateral boundary of the ethmoid sinus
    • The nasal bone is also frequently fractured
    • The cause is usually a large object such as baseball, fist, automobile accidents, tennis ball and kick
    Clinical Findings
    • Pain and tenderness
    • Diplopia on upward gaze
      • Due to entrapment of the inferior rectus and sometimes the inferior oblique muscles
    • Enophthalmos
      • Usually following initial swelling and proptosis
    • Patient reports feeling of pressure in orbit when attempting to blow nose
    • Facial anesthesia due to entrapment of the infraorbital nerve
    • Epistaxis
    Imaging Findings
    • CT of the facial bones is the imaging study of choice
    • Orbital emphysema
    • Fracture of the floor or medial wall of the orbit
      • Depression of the fracture fragment(s)
    • Soft-tissue mass extending into the maxillary sinus
    • Complete or partial opacification of the ipsilateral maxillary sinus from hemorrhage or edema
    Treatment and complications
    • Requirement for, timing of and method used for reconstruction of orbital floor is controversial
    • Surgical repair, when performed, usually occurs after swelling has subsided
      • If the diplopia does not resolve spontaneously
      • Severe enophthalmos (>2mm)
      • Large fractures (50% or more of floor)
    • Consists usually of resection of periosteum and repair of hole using either bone graft, plate or synthetic material such as Teflon
    • Long-standing entrapment can lead to vision impairment and enophthalmos

 

 

Blowout fracture of the orbit . Reformatted coronal CT of the facial bones demonstrates a fracture of the floor of the left orbit (white arrow) associated with orbital emphysema (blue arrow). A portion of the inferior rectus muscle (solid red arrow) projects into the maxillary sinus below (see normal opposite side--broken red arrow). There is blood in the maxillary sinus (white arrow). .
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