25 year old man who presents to ER after being involved in an "altercation". Complains of blurred vision in left eye.
Limited and painful upward gaze, left eye
Orbital floor fracture with bone fragment lying just beneath the optic nerve.
Surgical removal of bone fragments with reconstruction of the orbital floor
When an object of large diameter (greater than 4-5 cm) like a fist or a baseball, strikes the orbit, forces may be transmitted through increased intra-orbital pressure. When there is increased pressure in the orbit, the thinnest bones break first, and the orbital contents may herniate through the fracture. This is the so-called "Blow-out Fracture". Typically, the floor of the orbit, parts of the medial wall (lamina papyracea) and rarely the orbital roof may "blowout".
Clinical signs of entrapment (abnormal EOM's with restricted upward gaze) and enophthalmos (retraction of the eyeball) may occur.
Complications of Blow-Out Fx:
Cellulitis and Abscess
Diplopia and Restricted EOM's
Blunt force trauma (e.g. Ball or fist)
Hydraulic (pressure) forces increased intra-orbital pressure
Fractures thin bones
Floor (orbital process of maxilla)
Medial (20-50%) (lacrimal and ethmoid)
Herniation and entrapment of orbital fat & EOM (inf. Oblique)
The literature continues to emphasize this "Hydraulic Theory" over the alternative hypothesis of direct transmission of forces from the orbital rim and/or the globe itself.
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