- Orbital floor fractures may occur in isolation (“blowout” fractures) or as part of a zygomaticomaxillary complex fracture.
- Normal orbital volume ∼30 mL
- Facial bones making up the bony orbit: Frontal, maxilla, zygoma, ethmoid, lacrimal, greater and lesser wings of the sphenoid, and palatine bones.
- Blunt trauma to the midface (M/C)
Bone-conduction theory:A force, not powerful enough to fracture the rim, will propagate along the bone to fracture the weaker orbital floor (Le Fort).
Globe-to-Wall Theory:When a force pushes the globe into the orbit and causes the globe to contact the orbital floor, resulting in a floor fracture.
Hydraulic mechanism:Fracture is the result of increased intra-orbital pressure from the eye entering the orbit and not due to direct contact
- Diplopia (M/C complication)
- Frank muscle entrapment:
- Limited upward gaze
- Vertical diplopia
- Ocular movement restriction
- Infraorbital nerve numbness
- Reduced vision
- Enophthalmos or hypoglobus (anatomic & volumetric changes of bony orbit affecting globe position)
Forced duction test:
X-ray skull (Water’s view):
- Hanging drop/teardrop sign: Orbital contents herniating through floor of orbit into maxillary antrum (CHARACTERISTIC)
Computed tomography (CT):Ideal in the trauma setting to assess the orbit and to evaluate for cranial or other extraorbital injuries
- Infection of implanted material
- Implant migration
- Worsening diplopia
- Lower-lid retraction
- Blindness (d/t retrobulbar hemorrhage (RBH) or injury to the optic nerve)