NOE - naso-orbital ethmoid

NEC - naso-ethmoid complex

Naso ethmoid orbital

Naso-orbital ethmoidal

The nasoorbitoethmoidal (NOE) fracture refers to injuries involving the area of confluence of the nose, orbit, ethmoids, the base of the frontal sinus, and the floor of the anterior cranial base.

NOE fractures, by definition, are a different entity than isolated nasal bone fractures. However, they are often associated with fractures of the nasal bones.

The NOE complex, as seen in the image represents the confluence of the nasal, lacrimal, ethmoid, maxillary, and frontal bones

The paired nasal bones attach to the frontal bone superiorly and to the frontal process of the maxilla laterally.

The ethmoid bone is located posterior to the nasal bones.

The ethmoid labyrinth separates the orbits from the nasal cavity, while the fovea ethmoidalis forms the roof of the ethmoid sinuses laterally.

The cribriform plate is located approximately 1 cm inferior to the fovea ethmoidalis, and it forms the roof of the nasal cavity medially.

the foundation of NOE complex is two mIdline facial buttresses runs vertically from pyriform rim up to frontal bar.

These buttresses support the nasal projection and attachment of MCL.

The medial canthal tendon arises from the anterior and posterior lacrimal crests and the frontal process of the maxilla. The medial canthal tendon surrounds the lacrimal sac and diverges to become the orbicularis oculi muscle, tarsal plate, and suspensory ligaments of the eyelids. 

Sac is wrapped by lacrimal fascia Wrapped by MCL fascia. deep portion of orb oculi muscle attaches

posterior to post limb of MCL

NOE fractures are most commonly classified according to Markowitz BL, Manson PN, Sargent L, et al (1991)

Type I Type II Type III These can be unilateral or bilateral injuries.

Plast Reconstr Surg. 87(5):843-53:

In unilateral Markowitz type I fractures, there is a single large NOE fragment bearing the medial canthal tendon.

The nasal bone may also be involved and, in cases of comminution, may not provide adequate dorsal support to the nasal bridge.

In unilateral type II fractures, there is often comminution of the NOE area, but the canthal tendon remains attached to a fragment of bone, allowing the canthus to be stabilized with wires or a small plate on the fractured segment

The nasal bone may also be involved and, in cases of comminution, may not provide adequate dorsal support to the nasal bridge.

bone grafting of the nasal dorsum may be necessary

In type III fractures, there is often comminution of the NOE area (as in type II fractures) and a detachment of the medial canthal tendon from the bone.

Reestablishing the bony & soft tissue architecture of NOE region

Orbital volume, integrity

Integrity of medial canthus

Status of nasal support

Function of frontal sinus

Lacrimal drainage system

 perfect reduction of the frontal process of the maxilla

internal fixation to maintain its proper position. This could include 1-, 2-, or 3-point fixation.

require an extended glabellar approach or a transconjunctival approach with medial extension for fixation at this fracture site

The canthal-bearing bone fragment requires exact repositioning. 

The intercanthal distance should be restored.

nasal projection should be restored by addressing nasal bone fractures and by adding bone graft if necessary. 

Rule out CSF leak particularly in bilaterally displaced fractures in order to minimize the risk of early or delayed meningitis.

Transnasal wireThe transnasal wire technique may be necessary to properly reposition and fix the bone fragments.

When confronted with a NOE fracture requiring a transnasal wire, it is important to place the wire fixation in its proper posterior position.

medial canthus has become detached from the bone. A transnasal canthopexy must be performed.

The most important aspect is the medial and posterior positioning of the medial canthal ligament. 

 In order to accomplish this, a cantilever technique (plate 4 in the illustration) may be utilized

NOE injuries have been the most complex and difficult facial fractures to treat.

The complex anatomy of the region and difficulty with access makes the repair of NOE fracture a challenging task .

The complete knowledge including etiology, surgical anatomy, and classification with proper examination of patient and treatment planning will lead to better management of patients with NOE fractures .