Orbital fractures

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Cite this article as:
Kelly, O. Orbital fractures, Don't Forget the Bubbles, 2020. Available at:
http://doi.org/10.31440/DFTB.21843

Epidemiology

Facial fractures in children accounted for just 4.6% of paediatric trauma admissions on review of the American National Trauma Databank. However, even though they are less prevalent than in an adult population, they are associated with other severe injuries and higher mortality compared with adults. The pattern of injury descends the face as the patient ages – the under 5s are more likely to sustain frontal bone and orbital roof fractures, while the 6-16-year-olds are more likely to have midface and mandibular fractures. Orbital fractures as a subset comprise between 5 to 25% of facial fractures.

 

Anatomy

  • The orbit is comprised of 7 bones – maxilla, zygomatic, frontal, ethmoid, lacrimal, sphenoid and palatine.
  • The rim is formed by the frontal bone, maxilla, and zygoma.
  • The orbits are pyramidal structures, with a wide base opening on the face, with its apex extending posteromedially.
  • They lie anterior to the middle cranial fossa and inferior to the anterior cranial fossa.
  • Their close proximity to the sinuses coupled with the ophthalmic veins communicating with the cavernous sinus creates a possible introduction of infection into the intracranial cavity.

 

  • The infra-orbital nerve exits through the inferior orbital foramen inferior to the orbital rim and innervates lateral aspect of the external nose, inferior eyelid and cheek and upper lip and related oral mucosa.
  • Paediatric anatomy and development confer different injuries depending on age, with orbital floor fractures becoming more common than roof fractures at approximately age 7 due to the development of the maxillary sinus.

 

History and Examination

Mechanism of injury is always important to elicit in trauma as well as careful and thorough (and documented) examination. Initial assessment as always in trauma is by the ATLS ABC approach followed by a careful secondary survey.

Children are prone to a pronounced oculocardiac reflex which may become apparent in the initial ABC assessment; this is caused by compression of the globe or traction on the extra-ocular muscles. Connections between the sensory afferent fibres of the ophthalmic division of the trigeminal nerve and visceral motor nucleus of the vagus nerve cause bradycardia and hypotension often with headache, nausea, and vomiting.

Have a systematic approach to examination so as to ensure all important aspects are covered. Always examine and document:

  • General inspection – oedema, laceration, and bruising
  • Enophthalmos/proptosis
  • Subconjunctival haemorrhage
  • Periorbital emphysema
  • Pupillary response including RAPD
  • Eye movements in all directions
  • Visual acuity
  • Diplopia
  • Palpation of the orbital rim for tenderness or step
  • Abnormalities of the nasal bridge (saddle nose deformity) and widening of the midface (telecanthus)
  • Disruption to the infraorbital nerve: numbness of the ipsilateral cheek, lip, and upper gum

Sensory distribution of infra-orbital nerve

 

Investigation and Management

Investigation of orbital fractures is by x-ray and CT, with CT being the modality of choice, though it can be unreliable in children with blowout fractures. A CT may already be appropriate due to a mechanism of injury or red flags for a head injury.

The aim of initial management in the ED is to prevent further damage to the globe.

Patients should be advised to not blow their nose and to sneeze with their mouths open. A cold compress and raising the head of the bed can help alleviate periorbital oedema. Ensure the eyelids can close fully and lubricate the cornea. Provide a protective patch if necessary.

Types of Injuries

 Orbital Floor and Medial Orbital Wall Fractures

The term ‘blow out fracture’ has historically meant a fracture of the orbital floor secondary to a direct blow to the globe, causing an increase in pressure that results in the thin orbital floor fracturing. Children presenting with floor or medial wall fractures are at high risk of entrapment, as paediatric bones are more prone to greenstick fracture, which then creates a ‘trapdoor’ effect ensnaring the inferior oblique and inferior rectus muscles or other orbital contents. Clinically, the child will be unable to complete upwards gaze. Entrapment is a surgical emergency, as ischaemia of the involved musculature can cause permanent damage. The infraorbital nerve is commonly damaged in these injuries.

Orbital blow out fracture: the orbital floor has fractured, the inferior rectus muscle has herniated through, and then become trapped in a bony trapdoor. Reproduced with permission from AO Surgery Reference, www.aosurgery.org. Copyright by AO Foundation, Switzerland.

 

Children with orbital floor fractures may not have any facial bruising, classically presenting with a ‘white-eyed’ fracture with the only sign being limitation of eye movement secondary to entrapment.

(A) Restriction of upgaze in the right eye with no evidence of periocular trauma. (B) CT scan of the orbits demonstrating inferior rectus muscle entrapped within inferior orbital wall fracture (arrow). Reproduced with permission from www.emj.bmj.com

 

Orbital Roof Fractures

Orbital roof fractures are more common in childhood as the frontal sinus has not yet pneumatised, therefore all posterior force to the superior orbital rim is transferred to the anterior cranial base. Another mechanism of injury is a ‘blow-in’ fracture, where there is an inferiorly directed supraorbital force.

 

NOE (nasal-orbital-ethmoidal) Fractures

Nasal bone injuries are common in older children and adults and must always be assessed for an underlying NOE fracture. When direct force is applied to the nasal bone, it can cause a collapse of the paired nasal, lacrimal, and ethmoidal bones. If this fracture is missed in a child, significant midface deformities can result.

 

Midfacial fractures

Although children are more likely than adults to suffer isolated orbital rim fractures, orbital fractures are often involved in midfacial fractures of the maxilla and zygoma: the orbit is involved in Le Fort II and III; zygoma fractures are often accompanied by orbital floor or medial wall fractures.

 

Globe Injuries

Orbital fractures can often result in globe injuries ranging from corneal abrasion to rupture. If there are any signs of globe rupture (360 degrees conjunctival haemorrhage, misshapen pupil or a flat anterior chamber) a gross visual examination should be completed, vaulted eye protection applied, and immediate ophthalmology consult sought. Do not apply pressure to a possibly ruptured globe.

 

Retrobulbar haemorrhage

A rare but sight-threatening complication is a retrobulbar haemorrhage which causes increased pressure, stretching of the optic nerve and can result in permanent blindness. If optic pressure is low, medical management with mannitol, steroids, and acetazolamide can be used after expert involvement. However, if there is an indication that the pressure is high, a lateral canthotomy should be performed as a matter of urgency. The procedure should ideally be performed by an ophthalmologist, but when ophthalmology are delayed or unavailable, the procedure must be performed by an emergency clinician in the ED. Do not delay a lateral canthotomy for imaging if sight is threatened.

 

Indications for lateral canthotomy include:

  • Retrobulbar haematoma
  • Decreased visual acuity
  • Afferent pupillary defect
  • Proptosis

 

Pearls

  • Repeat a child’s eye examination while they are in the emergency – repeated examination can drastically change disposition from maxillofacial non-urgent transfer to a blue light ophthalmological review
  • Oculo-cardiac reflex can cause bradycardia and hypotension
  • Children are more likely to have other and significant injuries: the secondary and tertiary survey is imperative.
  • Children are more likely to suffer ‘trapdoor’ floor fractures causing entrapment that can present as a ‘white eye’ fracture– this is a surgical emergency, act fast.
  • Patients should avoid nose blowing and should sneeze with their mouth open following injury.
  • Ophthalmological assessment should be sought in all patients with orbital trauma.

 

Selected references

Imahara SD, Hopper RA, Wang J, Rivara FP, Klein MB. Patterns and outcomes of pediatric facial fractures in the United States: a survey of the National Trauma Data Bank. J Am Coll Surg. 2008;207:710–716

Oppenheimer AJ, Monson LA, Buchman SR. Pediatric orbital fractures. Craniomaxillofac Trauma Reconstr. 2013;6(1):9–20.

Koltai PJ, Amjad I, Meyer D, Feustel PJ. Orbital fractures in children. Arch Otolaryngol Head Neck Surg. 1995;121:1375–1379

Cohen SM, Garrett CG. Pediatric orbital floor fractures: nausea/ vomiting as signs of entrapment. Otolaryngol Head Neck Surg. 2003;129:43–47

Grant JH III, Patrinely JR, Weiss AH, Kierney PC, Gruss JS. Trapdoor fracture of the orbit in a pediatric population. Plast Reconstr Surg. 2002;109:482–489; discussion 490–495

Boyette, J. R., Pemberton, J. D., & Bonilla-Velez, J. (2015). Management of orbital fractures: challenges and solutions. Clinical ophthalmology. 2015;9:2127–2137.

Cobb ARM, Jeelani NO, Ayliffe PR. Orbital fractures in children. British Journal of Oral and Maxillofacial Surgery. 2013;41–46

Kassam K, Rahim I, Mills C. Paediatric orbital fractures: the importance of regular thorough eye assessment and appropriate referral. Case Rep Emerg Med. 2013:376564. doi:10.1155/2013/376564

About 

Orla Kelly is an emergency medicine trainee with an economics degree – frequently found frowning at the frivolous use of IV paracetamol and other expenses in the department. Passionate about recycling and the environmental impact of healthcare waste. When not at work can be found at a rugby match or drafting a screenplay loosely based on past experiences – ‘Bridget Jones’ Infirmary’.

Author: Orla Kelly Orla Kelly is an emergency medicine trainee with an economics degree – frequently found frowning at the frivolous use of IV paracetamol and other expenses in the department. Passionate about recycling and the environmental impact of healthcare waste. When not at work can be found at a rugby match or drafting a screenplay loosely based on past experiences – ‘Bridget Jones’ Infirmary’.

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