- Published on
Emergency and Acute Medicine – Blow-Out Fracture
Overview and Definitions
A blow-out fracture is an orbital floor fracture without orbital rim involvement. It follows sudden blunt trauma to the globe—classically from a projectile larger than half the size of a fist—with force transmitted through the noncompressible globe to the weakest point: the orbital floor. Because the orbital floor forms the roof of the maxillary and ethmoid sinuses, fracture can create communication between these spaces, causing orbital emphysema. The orbit contains fat that stabilizes the globe; fracture may allow herniation of orbital fat into the maxillary/ethmoid sinuses, producing enophthalmos from increased orbital volume and sinus congestion, with possible fluid collection from edema/bleeding. The infraorbital nerve runs in a bony canal ~3 mm below the floor; injury can cause hypoesthesia of the ipsilateral cheek and upper lip. To differentiate swelling-related numbness from nerve injury, test sensation on the ipsilateral gingiva (infraorbital distribution). The inferior rectus and inferior oblique course along the floor; restriction may occur from entrapment, contusion, or cranial nerve dysfunction—typically diplopia on upward gaze and impaired elevation on exam. The medial rectus lies above the ethmoid sinus and is less often entrapped; when involved, it causes diplopia on ipsilateral lateral gaze.
Etiology
Occurs when a projectile strikes the globe and the transmitted force fractures the orbital floor. Common projectiles include paintball, handball, racquetball, baseball, rock, or possibly a fist (larger projectiles may be blocked by the orbital rim). Blow-out fractures are also seen after MVCs, the most common cause of maxillofacial trauma.
Pediatric Considerations
Children more often have orbital roof fractures with associated CNS injuries. Orbital floor fractures are unlikely before age 7 because the floor is less weak prior to sinus pneumatization. However, children can sustain fractures with unrecognized rectus entrapment—the “white-eyed” fracture—often presenting with nausea, vomiting, headache, and irritability that mimic head injury and distract from the ocular diagnosis.
Clinical Features
Typical findings include periorbital tenderness, swelling, and ecchymosis. Ocular motility issues include restricted upward gaze (inferior rectus entrapment) and restricted ipsilateral lateral gaze (medial rectus entrapment). Infraorbital hypoesthesia may extend to the upper lip. Enophthalmos may be present from fat displacement. Periorbital emphysema can occur from sinus communication. Epistaxis is possible. Visual acuity is typically normal; decreased acuity suggests more extensive injury. There is no orbital rim step-off (by definition).
Associated Severe Injuries and Complications
Ocular injuries may include ruptured globe (up to 30%; ophthalmologic emergency), retrobulbar hemorrhage, and emphysematous optic nerve compression. Cervical spine and intracranial injuries may coexist. Common associated ocular findings: subconjunctival hemorrhage, corneal abrasion/laceration, hyphema, traumatic mydriasis, traumatic iridocyclitis (uveitis). Less common: iridodialysis, retinal detachment, vitreous hemorrhage, optic nerve injury. Associated fractures include nasal bone, zygomatic arch, and Le Fort fractures. Late complications include sinusitis, orbital infection, permanent extraocular movement restriction, and enophthalmos.
History and Physical Examination
History often includes being struck in the eye by a projectile. Perform a thorough ophthalmologic exam and palpate orbital bones for step-off, but avoid pressure on the globe until rupture is excluded. Desmarres lid retractors may be needed with significant lid swelling. Document pupillary responses and visual acuity (use handheld methods; Rosenbaum card is useful). Assess extraocular movements for disconjugate gaze/diplopia. Test sensation in the infraorbital nerve distribution (including ipsilateral gingiva). Examine lids/adnexa for emphysema. Perform slit-lamp and fundoscopic exams for associated injuries. Complete a full exam for other injuries and neurologic impairment.
Diagnostic Testing and Imaging
Labs: pre-op labs if indicated; pregnancy test prior to radiography when appropriate.
Imaging: If CT is unavailable/contraindicated, plain radiographs can help: facial films, Waters view and exaggerated Waters—classic “teardrop sign” (herniated orbital contents into ipsilateral maxillary sinus), maxillary sinus opacification/air–fluid level (less specific), visible floor fracture, and orbital lucency consistent with emphysema. CT is preferred to define anatomy; obtain axial and coronal 1.5-mm cuts. True coronal acquisition is preferred, but reconstructed coronals are acceptable if positioning is not possible.
Procedure: Forced duction test helps distinguish entrapment from nerve dysfunction—apply topical anesthesia to the conjunctiva on the opposite side and pull the globe away from the suspected entrapment; restricted mobility = positive, indicating physical entrapment.
Pediatrics: Orbital CT is the study of choice; plain films are less helpful. Early identification of entrapment is critical because delayed diagnosis worsens long-term outcomes; early surgical intervention can significantly improve results.
Differential Diagnosis
Cranial nerve palsy, orbital cellulitis, periorbital cellulitis, periorbital contusion/ecchymosis, retrobulbar hemorrhage, ruptured globe.
Management
Prehospital: If globe injury is possible, place a metal protective eye shield and keep patient supine.
Initial stabilization: Evaluate for intracranial/cervical spine injuries, rule out ruptured globe, and check visual acuity (decrease suggests more extensive injury).
ED care (after globe rupture excluded): Apply cool compresses for 24–48 hr to reduce swelling and potentially minimize/reverse herniation and avoid surgery. Instruct to avoid Valsalva and nose blowing to prevent compressive orbital emphysema. Provide prophylactic antibiotics, nasal decongestants if not contraindicated, analgesia, and tetanus prophylaxis.
Medications
Prophylactic antibiotics (to reduce risk of sinusitis/orbital cellulitis): Cephalexin 250 mg q6h for 10 days.
Systemic corticosteroids (advocated by some to hasten edema resorption and better assess entrapment/orbital damage): Prednisone 60–80 mg/day, start within 48 hr, continue 5 days.
Nasal decongestant: Phenylephrine nasal spray BID for 2–4 days (if not contraindicated).
Disposition and Follow-Up
Admission is rare; ~85% resolve without surgery. Consult facial trauma in the ED and consider admission/urgent management if: ≥50% floor fracture, diplopia or entrapment (especially in children), or enophthalmos >2 mm. Most patients can be observed 10–14 days until swelling resolves, then follow up with facial trauma surgeon to decide on surgical repair.
Follow-Up Advice
Symptoms should gradually improve. Return to the ED for increasing swelling, tenderness, redness, or pain, and for any visual disturbance, vision loss, or increasing eye pain.
Clinical Insights and Common Errors
Be extremely vigilant with pupillary responses and visual acuity—abnormalities may be the earliest sign of serious complications such as globe rupture or optic nerve injury from emphysematous/retrobulbar compression. Carefully assess for muscle entrapment in all patients, especially children, to avoid missing white-eyed fractures and long-term sequelae. Watch for the oculocardiac (Aschner) reflex—bradycardia triggered by extraocular muscle traction or globe compression—more common in children; treat by removing the stimulus, and atropine may be required in some cases.
Overview and Definitions
A blow-out fracture is an orbital floor fracture without orbital rim involvement. It follows sudden blunt trauma to the globe—classically from a projectile larger than half the size of a fist—with force transmitted through the noncompressible globe to the weakest point: the orbital floor. Because the orbital floor forms the roof of the maxillary and ethmoid sinuses, fracture can create communication between these spaces, causing orbital emphysema. The orbit contains fat that stabilizes the globe; fracture may allow herniation of orbital fat into the maxillary/ethmoid sinuses, producing enophthalmos from increased orbital volume and sinus congestion, with possible fluid collection from edema/bleeding. The infraorbital nerve runs in a bony canal ~3 mm below the floor; injury can cause hypoesthesia of the ipsilateral cheek and upper lip. To differentiate swelling-related numbness from nerve injury, test sensation on the ipsilateral gingiva (infraorbital distribution). The inferior rectus and inferior oblique course along the floor; restriction may occur from entrapment, contusion, or cranial nerve dysfunction—typically diplopia on upward gaze and impaired elevation on exam. The medial rectus lies above the ethmoid sinus and is less often entrapped; when involved, it causes diplopia on ipsilateral lateral gaze.
Etiology
Occurs when a projectile strikes the globe and the transmitted force fractures the orbital floor. Common projectiles include paintball, handball, racquetball, baseball, rock, or possibly a fist (larger projectiles may be blocked by the orbital rim). Blow-out fractures are also seen after MVCs, the most common cause of maxillofacial trauma.
Pediatric Considerations
Children more often have orbital roof fractures with associated CNS injuries. Orbital floor fractures are unlikely before age 7 because the floor is less weak prior to sinus pneumatization. However, children can sustain fractures with unrecognized rectus entrapment—the “white-eyed” fracture—often presenting with nausea, vomiting, headache, and irritability that mimic head injury and distract from the ocular diagnosis.
Clinical Features
Typical findings include periorbital tenderness, swelling, and ecchymosis. Ocular motility issues include restricted upward gaze (inferior rectus entrapment) and restricted ipsilateral lateral gaze (medial rectus entrapment). Infraorbital hypoesthesia may extend to the upper lip. Enophthalmos may be present from fat displacement. Periorbital emphysema can occur from sinus communication. Epistaxis is possible. Visual acuity is typically normal; decreased acuity suggests more extensive injury. There is no orbital rim step-off (by definition).
Associated Severe Injuries and Complications
Ocular injuries may include ruptured globe (up to 30%; ophthalmologic emergency), retrobulbar hemorrhage, and emphysematous optic nerve compression. Cervical spine and intracranial injuries may coexist. Common associated ocular findings: subconjunctival hemorrhage, corneal abrasion/laceration, hyphema, traumatic mydriasis, traumatic iridocyclitis (uveitis). Less common: iridodialysis, retinal detachment, vitreous hemorrhage, optic nerve injury. Associated fractures include nasal bone, zygomatic arch, and Le Fort fractures. Late complications include sinusitis, orbital infection, permanent extraocular movement restriction, and enophthalmos.
History and Physical Examination
History often includes being struck in the eye by a projectile. Perform a thorough ophthalmologic exam and palpate orbital bones for step-off, but avoid pressure on the globe until rupture is excluded. Desmarres lid retractors may be needed with significant lid swelling. Document pupillary responses and visual acuity (use handheld methods; Rosenbaum card is useful). Assess extraocular movements for disconjugate gaze/diplopia. Test sensation in the infraorbital nerve distribution (including ipsilateral gingiva). Examine lids/adnexa for emphysema. Perform slit-lamp and fundoscopic exams for associated injuries. Complete a full exam for other injuries and neurologic impairment.
Diagnostic Testing and Imaging
Labs: pre-op labs if indicated; pregnancy test prior to radiography when appropriate.
Imaging: If CT is unavailable/contraindicated, plain radiographs can help: facial films, Waters view and exaggerated Waters—classic “teardrop sign” (herniated orbital contents into ipsilateral maxillary sinus), maxillary sinus opacification/air–fluid level (less specific), visible floor fracture, and orbital lucency consistent with emphysema. CT is preferred to define anatomy; obtain axial and coronal 1.5-mm cuts. True coronal acquisition is preferred, but reconstructed coronals are acceptable if positioning is not possible.
Procedure: Forced duction test helps distinguish entrapment from nerve dysfunction—apply topical anesthesia to the conjunctiva on the opposite side and pull the globe away from the suspected entrapment; restricted mobility = positive, indicating physical entrapment.
Pediatrics: Orbital CT is the study of choice; plain films are less helpful. Early identification of entrapment is critical because delayed diagnosis worsens long-term outcomes; early surgical intervention can significantly improve results.
Differential Diagnosis
Cranial nerve palsy, orbital cellulitis, periorbital cellulitis, periorbital contusion/ecchymosis, retrobulbar hemorrhage, ruptured globe.
Management
Prehospital: If globe injury is possible, place a metal protective eye shield and keep patient supine.
Initial stabilization: Evaluate for intracranial/cervical spine injuries, rule out ruptured globe, and check visual acuity (decrease suggests more extensive injury).
ED care (after globe rupture excluded): Apply cool compresses for 24–48 hr to reduce swelling and potentially minimize/reverse herniation and avoid surgery. Instruct to avoid Valsalva and nose blowing to prevent compressive orbital emphysema. Provide prophylactic antibiotics, nasal decongestants if not contraindicated, analgesia, and tetanus prophylaxis.
Medications
Prophylactic antibiotics (to reduce risk of sinusitis/orbital cellulitis): Cephalexin 250 mg q6h for 10 days.
Systemic corticosteroids (advocated by some to hasten edema resorption and better assess entrapment/orbital damage): Prednisone 60–80 mg/day, start within 48 hr, continue 5 days.
Nasal decongestant: Phenylephrine nasal spray BID for 2–4 days (if not contraindicated).
Disposition and Follow-Up
Admission is rare; ~85% resolve without surgery. Consult facial trauma in the ED and consider admission/urgent management if: ≥50% floor fracture, diplopia or entrapment (especially in children), or enophthalmos >2 mm. Most patients can be observed 10–14 days until swelling resolves, then follow up with facial trauma surgeon to decide on surgical repair.
Follow-Up Advice
Symptoms should gradually improve. Return to the ED for increasing swelling, tenderness, redness, or pain, and for any visual disturbance, vision loss, or increasing eye pain.
Clinical Insights and Common Errors
Be extremely vigilant with pupillary responses and visual acuity—abnormalities may be the earliest sign of serious complications such as globe rupture or optic nerve injury from emphysematous/retrobulbar compression. Carefully assess for muscle entrapment in all patients, especially children, to avoid missing white-eyed fractures and long-term sequelae. Watch for the oculocardiac (Aschner) reflex—bradycardia triggered by extraocular muscle traction or globe compression—more common in children; treat by removing the stimulus, and atropine may be required in some cases.
0 Comments
