What Are NOE Fractures?

Complex Facial Injuries

In This Article

Nasoorbitoethmoid (NOE) refers to the anatomical complex involving the nasal, orbital, and ethmoid bones of the face. NOE fractures usually result from high-impact blunt trauma to the nasal region forcing depression of the nasal bones into the orbital and/or ethmoid bones.

While the NOE complex typically refers to these associated bones, NOE fractures may include damage to bones, blood supply, nerves, and other supporting structures of the mid-facial region. The force and point of impact determine the extent of injuries. Commonly associated causes of NOE fractures include falls, motor vehicle accidents, and contact sports.

NOE Complex Anatomy

While the NOE complex commonly refers to the three main structures of this anatomical complex, the complex actually refers to a region involving six categories of facial structures. Bones are one of the major components of the NOE complex including:

  • nasal bones
  • nasal process of the frontal bone
  • nasal process of the maxilla
  • lesser wing of the sphenoid bone (also known as orbitosphenoid bones)
  • lacrimal bone
  • lamina papyracea (also known as orbital lamina of the ethmoid bone)
  • cribriform plate and perpendicular plate of the ethmoid bone

Other components of the NOE complex includes:

  • sinus cavities formed from the bones listed above
  • medial canthal tendon, a tendon connected at the inside corner of the eye, connecting bone to eyelids that serves as an important feature in the lacrimal pump
  • nasal lacrimal duct components (lacrimal fossa, lacrimal sac, superior, and inferior canaliculi
  • nerves (ophthalmic, maxillary, olfactory, and ethmoid nerves)
  • arteries (ethmoid and maxillary arteries)
  • structures associated with the orbital bone (orbital fat, medial rectus muscle, superior oblique muscle, and trochlea)
  • buttresses of the face (areas of increased thickness that serve as support structures for other facial structures such as the eyes, dentition, airways, and muscle)

Signs and Symptoms

As you can see with the many involved anatomical structures listed above, there are many possible complications that can result from an NOE fracture.

Your distinct set of symptoms will be related to what specific damage to the NOE complex has occurred.

The most common symptoms that you will feel include diplopia (double vision), visual disturbances, pain in the eye, forehead, and nose, forehead paresthesia (abnormal sensations such as burning, itching, or numbness), nasal congestion, dizziness or vertigo, and/or anosmia (loss of smell).

While you may experience several subjective symptoms—related to how you feel and not what you can see—there are also several physical signs that your doctor will be looking for. These signs are considered objective, since you can see these complications related to NOE fractures. Physical signs of NOE fractures includes:

  • Severe epistaxis (nose bleed)
  • Epiphora (overflowing tears, signaling that the lacrimal duct is not draining appropriately)
  • Ocular injury (globe rupture or ruptured eye, lens dislocation, retinal detachment, or vitreous hemorrhage)
  • Cerebrospinal Fluid (CSF) Leak (noted as clear fluid draining from the nose)
  • Traumatic Telecanthus (increased distance between the pupils or medial canthus, or the inside corner of the eye)
  • Periorbital Ecchymoses (also called "raccoon eyes")

Not all injuries will be as severe as some of the signs or symptoms listed above. The severity and location of the blunt force trauma determine the severity of associated problems.

Prevalence

NOE Fractures represents approximately one out of every 20 facial injuries in adults and about three out of every 20 facial injuries in children. From these NOE fractures, approximately three out of 10 NOE fractures will include some sort of eye injury.

Motor vehicle accidents where unrestrained passengers are involved increases the risk of an NOE fracture from occurring.

Therefore, it is thought that NOE fractures are actually on a decline with the increased use of seat-belts and airbag implementation.

Diagnosis

Rapid diagnosis of NOE fractures is necessary in order to reduce long-term complications as well as aesthetic deformities. During the initial assessment, it is important for your doctor to differentiate an NOE fracture from an isolated nasal, orbital (eye), or ethmoid labyrinth (ethmoid sinus) injury.

Prior to any NOE fracture-related assessments, you will have a full-body trauma evaluation. This will help to ensure the most emergent risks are identified—in particular, adequate circulation, airway control, and breathing will be assessed. Due to the location of the trauma, you may be at risk for having complications with this. Proper precautions to protect your cervical spine may have already been initiated, as an injury to your cervical spine is also possible with this type of injury.

Head and Face Assessment

Initial head and face assessment begins with inspecting for ecchymoses (bleeding underneath the skin), any soft tissue injury, or any misaligned facial bones. A likely next assessment will be the intercanthal distance, which is the measurement of the distance between your medial canthus (inside corner of your eyes). The typical distance is around 25 to 35 millimeters, which is approximately half the distance between both pupils. You will be diagnosed with telecanthus if the distance is greater than 40 millimeters.

Further medial canthal tendon testing may include the bowstring test. Your doctor will grab your eyelashes and pull your eyelid laterally away from your nose while palpating the tendon in the corner of your eye. If you medial canthal tendon is intact, resistance (like a bowstring) will be felt. However, if the tendon has torn away, there will be no tension felt. This test is important in helping to stage the severity and type of an NOE fracture.

Nasal Evaluation

A nasal exam may require suctioning to clear any congestion prior to inserting a speculum or endoscope. Your doctor will be looking for mucosal (lining of the inside of the nose) tears, deviated septum, hematomas, or CSF leak. If you doctor notes clear or straw-colored fluid draining from your nose, or suspects that the back wall of sinus cavities has been damaged, they will test a drop of fluid on a piece of gauze or surgical towel and look for a "halo" effect.

In this test, the CSF spreads faster than other fluid, which creates the haloed image. The diagnostic laboratory test to check for CSF in nasal drainage is the beta-2 transferrin assay.

Primary and secondary Jones dye tests may be performed to determine patency of the lacrimal duct. In these tests, your doctor can use a fluorescent dye to determine if the dye remains in the eye or is transported through the lacrimal duct system into your nasal passages.

CT scans are the gold standard for rapid identification of NOE fractures. X-rays are very limited in their usefulness and a thorough physical exam is often more beneficial. Using two different CT views (axial and coronal), thorough viewing of the NOE and any intracranial complications can be visualized.

Treatment

Due to the many facial structures involved in the NOE complex, repairing an NOE fracture is one of the more challenging surgical reconstructions being performed. Complications related to surgeries to repair NOE fractures mirrors NOE fracture symptoms with the addition of scarring and infection.

NOE fractures are classified into three different severity categories based on the fracturing of bones and other structures in relation to the medial canthal tendon as outlined below:

  • Type-I Fractures: (also known as a unilateral Markowitz type 1 fracture): a single large fragment with the medial canthon tendon still attached
  • Type-II Fractures: may be either unilateral or bilateral. Involves multiple fragments of bone, with one fragment remaining attached to the medial canthal tendon.
  • Type-III Fractures: similar to Type-II fractures, however, there is a detachment of the medial canthal tendon from the fragments.

In Type-I and Type-II fractures, the nasal bones may or may not be fractured when fracturing is only on one side. In Type-II fractures that involve bilateral fractures, nasal bone fracturing is commonly present. In most Type-III fractures, the nasal bones are also fractured.

Repairing the bridge of your nose may require bone grafting in Type-II and Type-III fractures.

Related to the complexity of the surgeries, surgical interventions will start at the base of the skull for stability and the surgeon will work their way towards the mid-face. Early repairs will include realignment (reduction) and plating before proceeding to further repairs. Special attention is required in Type-III fractures to reconstruct the orbital wall (bones around the eye socket) and reattachment of the medial canthal tendon.

In Type-I and Type-II, only minimal wiring and plating may be required. Repairing the lacrimal duct system may require insertion of a tube to stabilize the duct.

Treatment of NOE fractures can be very successful, however, you may still have several scars ranging from small to large depending on the severity and location of fractures. Soft tissue damage as well can affect the cosmetic look of your face. If your orbital walls needed repair or you had eye damage, frequent eye exams will be necessary. Any vision changes requiring any type of an NOE fracture should be evaluated by an ophthalmologist as soon as possible.

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Article Sources

  • Nasoorbitoethmoid Fractures. Medscape. Updated on August 14, 2007.

  • Diagnosis: NOE fractures. AO Foundation.

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