Naso-orbitoethmoid (NOE) complex fracture

Naso-orbitoethmoid (NOE) fractures (also known as orbitoethmoid or nasoethmoidal complex fractures) are fractures which involve the central upper midface.

Pathology

Naso-orbitoethmoid fractures are caused by a high-impact force applied anteriorly to the nose and transmitted posteriorly through the ethmoid bone.

Associations

Associated injuries include:

• telecanthus secondary to medial canthal tendon injury
• nasolacrimal duct disruption and subsequent frontal mucocele formation
• orbital injuries and exophthalmos due to reduced intra-orbital volume
• cerebrospinal fluid rhinorrhea due to fracture through the cribriform plate
• epiphora secondary to nasolacrimal duct injury

Radiographic features

Comminution of both medial maxillary buttresses results in a pattern of fractures involving the nasal bones and septum, ethmoid sinuses, and medial orbital walls.

Classification

The Markowitz and Manson classification system categorizes fractures of the NOE complex as follows :

• type I: in which the medial canthal tendon is intact and connected to a single large fracture fragment
• type II: the fracture is comminuted, and the medial canthal tendon is attached to a single bone fragment
• type III: comminution extends to the medial canthal tendon insertion site on the anterior medial orbital wall at the level of the lacrimal fossa, with resultant avulsion of the tendon