Fracture, Blow Out



Ovid: 5-Minute Sports Medicine Consult, The


Fracture, Blow Out
Jayson Pereira
Basics
Pediatric Considerations
  • Orbital floor fractures: Extremely unlikely before 7 yrs of age
  • Lack of pneumatization of the paranasal sinuses: Orbital floor is not a weak point in the orbit.
  • Orbital roof fractures with associated CNS injuries more common
Description
  • Defined as an orbital wall fracture without orbital rim involvement owing to blunt trauma to the orbit
  • Force transmitted through the orbital structures to the weakest structural point—most commonly the orbital floor or medial wall—resulting in fracture
  • Trapdoor fracture (more common in children) is a linear fracture of the orbital bone that reduces spontaneously to original position, entrapping and strangulating infraocular soft tissue.
    • Usually an intraoperative diagnosis
    • Open door fracture is more common in adults.
  • Orbital floor serves as roof to air-filled maxillary and ethmoid sinuses. Communication between the spaces results in orbital emphysema.
  • Orbit contains fat, which holds the globe in place.
    • Orbital floor fracture may result in herniation of the fat on the inferior orbital surface into the maxillary or ethmoid sinuses.
    • Leads to enophthalmos owing to orbital volume loss
    • Sinus congestion and fluid collection occur secondary to edema.
  • Infraorbital nerve runs through the bony canal 3 mm below the orbital floor.
    • Injury results in hypoesthesia of the ipsilateral cheek.
    • Distinguished from hypoesthesia owing to swelling by testing for decreased sensation on the ipsilateral gingiva, which is within the infraorbital nerve distribution
  • Inferior rectus and inferior oblique muscles run along the orbital floor.
    • Restriction of these extraocular muscles occurs owing to entrapment within the fracture or contusion or cranial nerve dysfunction.
    • Diplopia on upward gaze
    • Inability to elevate the affected eye normally on examination
  • Medial rectus muscle is located above the ethmoid sinus.
    • Less commonly entrapped
    • Diplopia on ipsilateral lateral gaze
  • Oculocardiac reflex is defined as an increased vagal tone secondary to soft tissue entrapment. Signs and symptoms include nausea, vomiting, bradycardia, and syncope.
Epidemiology
  • Observed in any sport that puts the athlete at risk for forceful contact to the face.
  • Most common: Boxing, mixed martial arts, wrestling, rugby, soccer, basketball, action sports
  • Less common: Diving, gymnastics, cheerleading, baseball, handball
  • Object striking the orbital region is usually larger than orbital rim, such as a baseball or fist (1).
Diagnosis
Pediatric Considerations
  • Immature facial skeleton with lack of pneumatization of the paranasal sinuses makes plain radiographs of limited value.
  • Orbital CT scan: Study of choice
  • Thorough ophthalmologic examination:
    • Visual acuity (should not be affected)
    • Test extraocular movements for disconjugate gaze or diplopia.
    • Palpate bony structures for evidence of step-off.
    • Test sensation in inferior orbital nerve distribution.
    • Examine lid and adnexa.
    • Careful attention not to place pressure on the globe until ruptured globe excluded
    • Slit-lamp and funduscopic examination help to identify associated injuries.
  • Associated injuries:
    • Ocular injuries:
      • Ruptured globe (incidence 5–10% of blowout fractures) (2)
      • Subconjunctival hemorrhage
      • Corneal abrasion/laceration
      • Hyphema
      • Iridodialysis
      • Traumatic iridocyclitis (uveitis)
      • Traumatic mydriasis
      • Retinal detachment
      • Vitreous hemorrhage
      • Compressive orbital emphysema
      • Retrobulbar hemorrhage
      • Optic nerve injury
      • Central retinal artery occlusion
      • Acute angle glaucoma
    • Extraocular muscle entrapment:
      • Inferior rectus
      • Inferior oblique
      • Medial rectus (less common)
    • Infraorbital nerve injury
    • Facial fractures:
      • Nasal bones
      • Zygomatic arch fracture
    • Neck injuries
    • Intracranial injury
Physical Exam
  • Periorbital tenderness, swelling, ecchymosis
  • Impaired ocular mobility or diplopia:
    • Upward gaze impaired owing to inferior rectus entrapment
    • Ipsilateral lateral gaze impaired with medial rectus entrapment
  • Infraorbital hypoesthesia: Owing to compression/contusion of infraorbital nerve
  • Enophthalmos or hypoophthalmos: Owing to herniation of orbital fat through fracture
  • Periorbital emphysema
  • Normal visual acuity (unless associated ocular injury)
  • Epistaxis (indicative of medial wall injury)

P.171


Diagnostic Tests & Interpretation
  • Plain radiographs:
    • Facial films
    • Orbits
    • Water's view and exaggerated Water's view:
      • Classic “teardrop sign” illustrates herniated mass of orbital contents in the ipsilateral maxillary sinus.
      • Opacification of or air–fluid level in the ipsilateral maxillary sinus (less specific)
      • Orbital floor bony fracture
      • Lucency in orbits consistent with orbital emphysema (1)
  • CT scan of orbits:
    • If diagnosis in question and for follow-up
    • Defines involved anatomy
    • Obtain 1.5-mm cut (2).
    • Trapdoor type of fractures may be difficult to identify, even with CT scan
  • Forced duction test:
    • Distinguishes nerve dysfunction from entrapment
    • Topical anesthesia is applied to the conjunctiva on the opposite side, and the globe is pulled away from the expected point of entrapment. If the globe is not mobile, the test is positive.
Lab
Preoperative laboratory studies if indicated
Differential Diagnosis
  • Retrobulbar hemorrhage
  • Periorbital contusion/ecchymosis
  • Cranial nerve palsy
  • Ruptured globe
  • Orbital cellulitis
  • Periorbital cellulitis
Ongoing Care
Codes
ICD9
  • 802.6 Closed fracture of orbital floor (blow-out)
  • 802.7 Open fracture of orbital floor (blow-out)


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