blow-out fracture
Pronunciation: BLOW-owt
Orbital fracture involving the floor or medial wall with intact orbital rim.
Full Definition
A blow-out fracture is a specific type of orbital fracture characterized by disruption of the thin bones forming the orbital floor or medial wall while the stronger orbital rim remains intact. This injury pattern typically results from blunt trauma that increases intraorbital pressure, causing the weakest portions of the orbit to fracture and herniate orbital contents into adjacent spaces. Clinical signs include diplopia, enophthalmos, infraorbital nerve hypoesthesia, and restriction of extraocular movements. The fracture may be pure (isolated floor or medial wall) or impure (involving both floor and rim). Surgical indications include significant enophthalmos, persistent diplopia, or large fracture size with risk of late complications.
Usage
Usage note: Hyphenate as 'blow-out fracture' rather than 'blowout fracture' in medical documentation.
In Context
- "CT imaging revealed a large blow-out fracture of the left orbital floor with inferior rectus entrapment." — radiology report
- "The patient developed enophthalmos secondary to a medial wall blow-out fracture." — follow-up examination