Blow out Fracture

CT can fairly accurately determine the size of the fracture and its relationship to the orbital soft tissues. Computed tomography (CT) scanning has become an integral factor in the diagnosis and treatment of blow out fractures. CT provides excellent detail of the bones and the relationship with the extraocular muscles and orbital tissues. Coronal views can help distinguish whether the muscle itself is entrapped, which can be difficult to evaluate on clinical examination.

Medial part of floor of orbit

Blowout fractures mainly involve orbital floor and medial wall. When an external force is applied to the globe, intraorbital pressure increases to the point that one or more of the thin-walled bones of the orbit “blow-out” or fracture. The most common bone fractured is the maxillary bone which comprises the floor of the orbit. The orbital contents can be significantly displaced inferiorly after orbital blowout fracture.

“The most common site for a blowout fracture to occur is the posteromedial aspect of the orbital floor, medial to the infraorbital neurovascular bundle where the maxillary bone is very thin.” – The Internet Journal of Otorhinolaryngology

Investigation:

• Radiograph (Waters view) may see a soft tissue mass on the superior margin of the maxillary sinus, representing the herniated periorbital tissues into the sinus.
• Hanging drop or tear drop sign: hanging opacity of superior maxillary antrum.
• Computed tomography is the gold standard. Coronals provide best view. Extraocular muscle rounding and herniation of fat into maxillary sinus can be clearly viewed.

• Medical management for asymptomatic patients–IV antibiotics and short course of oral steriods.
• Surgical management for symptomatic patients.

D i.e. Posterior-medial wall of floor

B i.e. Inferior wall

Blow out fracture mainly involve orbital floor (inferior wall) & medial wall Q. It presents with hanging drop or tear drop sign Q.

Ans. ‘c’ Blow out fracture of the orbit 

Blow out fracture is isolated fracture of orbital floor, when a large blunt object strikes the globe. It presents with:

• Ecchymosis of lid, conjunctiva and sclera
• Enophthalmos
• Diplopia due to displacement of eye ball
• Anaesth esia of cheek and upper lip, if infraorbital nerve is involved.

Ans. Exophthalmos

Ans. Posteromedial floor of orbit

Ans. D: Floor

Critical signs of recent blow-out fracture include:

• Edema and ecchymosis of the lid tissues
• Restriction of ocular motility, especially with vertical movements
• Orbital crepitus (subcutaneous emphysema)
• Hypoesthesia of the ipsilateral cheek, due to entrapment of the infraorbital nerve.
• There may also be an associated nosebleed due to communication between the orbit and maxillary sinus.

Orbital edema initially surrounds and displaces the globe, in some cases causing the eye to appear proptotic.

However, as the swelling subsides, the eye is likely to drop down and back, becoming enophthalmic.

Associated traumatic uveitis and/or hyphema may be noted as well.

Most commonly the orbital floor ‘blows out’, but it can also affect the medial wall of the orbit.

Ans. Medial wall and floor or orbit

Ans. Blow out fracture

Ans. is ‘a’ i.e., Blow out fracture of orbit wall

Enophthalmos is seen in blow out fracture of orbit wall.