Naso-orbital ethmoid (NOE) fractures are common injuries found after high-velocity blunt trauma.
There have been varying trends, but motor vehicle collisions and interpersonal violence are the 2 most common causes of maxillofacial fractures. Falls and sports injuries are less common causes.
The male to female ratio of maxillofacial fractures is 2:1.
Ocular injury has been reported in 24%–28% of facial fracture cases. Cervical spine injury is also found in 1.3% of patients with facial fractures and 4% of patients with facial injury from motor vehicle collision.
Specifics of the trauma including
- Mechanism of injury
- Other interventions already undertaken
In conscious patients, history should focus on
- Prior facial trauma
- Prior ocular disease
- Point tenderness
- Nasal airway obstruction
- Review of prior photographs
In addition to facial fractures and ocular injury, care often needs to be coordinated with other teams caring for
- Cervical spine
- Any intracranial concerns
An NOE fracture centers on the frontal process of the maxilla and can also involve the ethmoid bone, lacrimal bone, nasal bone and frontal bone.
- The maxillary bone segment includes the inferior 2/3rds of the medial orbital rim and the lacrimal crests.
- The segment articulates with the medial orbital wall and nasal dorsum.
The inferior fracture line often extends through the inferior orbital rim lateral to the lacrimal crest connecting into the piriform aperture.
- The superior fracture line extends from the medial wall, through the medial rim above the canthal tendon, and into the nasal dorsum.
- As such, the fracture involves the medial canthal tendon–bearing bone segments and can lead to displacement or disruption (Figure 1).
An NOE fracture can occur in isolation from central midface trauma and is often bilateral in such circumstances.
- Nearby fractures of the frontal bone, frontal sinus, or inferior orbital rim are common in unilateral injuries.
- The NOE fracture is also a part of other named fracture patterns.
- Nasal fractures are classified by visualizing a coronal plane through the nasal bone where the fracture occurred, with Phase I being the most anterior portion.
- NOE fractures are elements of a Plane III nasal fracture.
- By definition, Phase III fractures through the nasal dorsum include the medial orbital rim.
- There is extensive literature regarding the management of nasal dorsum reconstruction, and the usage of bone or cartilage grafting might need to be considered.
- NOE fractures are also common elements of high Le Fort II fractures and Le Fort III fractures.
Figure 1. Complex facial fracture from a gunshot wound with a severely comminuted right NOE fracture (Type III) and less comminuted left NOE fracture (Type I).
- Clinical exam for standard signs of orbital and ophthalmic injury as well as various specific signs of an NOE or nasal bone fracture
- Periorbital bruising
- Nasal bone instability evaluated by pinching the nasal dorsum
- Telecanthus (greater than 40 mm intercanthal distance in any patient, less for Caucasians)
- Flattened nose with widened nasal dorsum
- Upturned nasal tip
- Narrowing of horizontal palpebral fissure
- Epistaxis, hematoma, or rhinorrhea on intranasal exam
- Subcutaneous emphysema
- Mobility or a "click" on palpation of the medial canthal tendon
- Signs of nasolacrimal duct obstruction
- CT scanning to evaluate the bone and soft tissue injury
- Thin-cut noncontrast maxillofacial CT scanning: Modern spiral scanning and thin cuts allows for multiplanar reformatting to view images in the coronal, axial and sagittal planes and also 3D reconstruction.
Testing for staging, fundamental impairment
The degree of bone comminution within the maxillary bone segment can be used to subclassify the fracture.
- This has implications for the canthal tendon's required management.
- Markowitz, Manson, et al. described 3 subtypes (Figure 2):
- Type I: Minimal comminution with the medial canthal tendon attached to a large bone segment
- Type II: Comminution of the bone fragments with the medial canthal tendon remaining attached to a bone fragment
- Type III: Comminution with disinsertion or disruption of the medial canthal tendon
Figure 2. Subclassifications of NOE fractures.
Seat belt has been reported to decrease the risk of maxillofacial injury by 72%.