Orbital blowout fractures
Anthony Greer
Blow out fractures
• Term "blow-out fracture" when describing inferior rectus entrapment with decreased ocular motility in the setting of an orbital floor fracture.
Orbital Anatomy
• The orbital plate of the maxilla joins the orbital plate of the zygoma and the orbital plate of the palatine bones to form the floor.
Mechanism
• The mechanism is controversial. • There are two main theories are a result of :
– The sudden increase in intraorbital pressure – "buckling" forces which are transmitted to the
orbital bones by transient deformity
Clinical Signs and symptoms
• Enophthalmos – recession of the eyeball within the orbit
• Diplopia – Double vision – especially on upward gaze– Due to inferior rectus entrapment
• Hypesthesia – Reduced sense of touch or sensation – Due to injury of infraorbital nerve – Usually have numbness of the gingiva and of the skin
of the midface
Coronal CT
• CTs are diagnostic method of choice
• Coronals provide best view
• CT can show – extraocular muscle
rounding– Herniation of fat into
maxillary sinus
Images – Coronal CT
• The image reveals herniation of fat into the left maxillary sinus
Coronal CTs
X-ray (waters view)
• Image shows depressed fragment of the left orbital floor (arrow) and an air-fluid level in the left maxillary sinus
Clinical Images
A) orbital floor fracture with hypoophthalmus and ptosis
The left eye fails to elevate in up-gaze (hypotropia).
Management
• Medical management for asymptomatic patients– IV antibiotics and short course of oral steriods
• Surgical management for symptomatic patients (occurs in most cases)
References
• Cruz, AA, Eichenberger, GC. Epidemiology and management of orbital fractures. Curr Opin Ophthalmol 2004; 15:416.
• Jatla, KK, Enzenauer, RW. Orbital fractures: a review of current literature. Curr Surg 2004; 61:25.
• Long, J, Tann, T. Orbital trauma. Ophthalmol Clin North Am 2002; 15:249.
• Burnstine, MA. Clinical recommendations for repair of orbital facial fractures. Curr Opin Ophthalmol 2003; 14:236.