Residency · Residency · Oral Maxillofacial Surgery

Naso-Orbitoethmoid Fractures

Overview

Naso-orbitoethmoid (NOE) fractures involve the confluence of the nasal bones, frontal process of the maxilla, lacrimal bones, ethmoid bones, and the medial orbital walls. The central fragment bearing the medial canthal tendon (MCT) insertion is the defining anatomic unit, and its management determines the surgical approach. These fractures result from high-energy direct impact to the nasal bridge area (MVC, assault, falls). The hallmarks are telecanthus, nasal dorsum depression, and potential CSF rhinorrhea. NOE fractures are among the most challenging facial fractures to manage, and inadequate treatment leads to persistent telecanthus and nasal deformity.

Anatomy

Central Fragment

The central fragment is the key anatomic unit in NOE fractures. It is the bone fragment bearing the insertion of the medial canthal tendon, located at the frontal process of the maxilla and lacrimal bone. The MCT inserts on both the anterior and posterior lacrimal crests.

Medial Canthal Tendon

The MCT maintains medial canthal position and globe-eyelid apposition. Its anterior limb inserts on the anterior lacrimal crest (frontal process of the maxilla) and is the strongest component. The posterior limb inserts on the posterior lacrimal crest (lacrimal bone) and is important for eyelid tension against the globe. The superior limb inserts on the frontal bone periosteum. Normal intercanthal distance is approximately 30-34 mm, or roughly half the interpupillary distance. Telecanthus refers to increased intercanthal distance due to lateral displacement of the MCT with its bony fragment.

Lacrimal System

The lacrimal sac sits in the lacrimal fossa between the anterior and posterior lacrimal crests. The nasolacrimal duct descends through the nasolacrimal canal to the inferior meatus. The system is frequently damaged in NOE fractures, which may cause epiphora.

Adjacent Structures

The ethmoidal arteries (anterior and posterior) carry risk of retrobulbar hematoma if lacerated. The cribriform plate forms the superior boundary, with risk of CSF leak. The medial orbital wall (lamina papyracea) is extremely thin and frequently comminuted.

Classification -- Markowitz and Manson

Type I

Type I involves a single large central fragment with the MCT attached. The MCT-bearing fragment is intact (not comminuted), and treatment by reduction and fixation of the fragment restores MCT position. This type carries the best prognosis.

Type II

Type II features a comminuted central fragment, but the MCT remains attached to an identifiable bone piece. The MCT-bearing fragment can be reduced and plated, though additional transnasal wiring for MCT support may be required.

Type III

Type III involves a severely comminuted central fragment where the MCT insertion is avulsed or cannot be identified on bone. The MCT is detached or the bone is too comminuted for plate fixation. This type requires transnasal canthopexy (wiring the MCT to the contralateral medial orbital wall) and carries the worst prognosis with the highest risk of persistent telecanthus.

<image>Anterior view illustrations of the three Markowitz-Manson NOE fracture types: Type I with a single central fragment bearing the intact medial canthal tendon insertion, Type II with comminution of the central fragment but an identifiable MCT-bearing segment, and Type III with severe comminution and loss of identifiable MCT insertion requiring transnasal canthopexy</image>

Clinical Presentation

Telecanthus presents as increased intercanthal distance (normal approximately 30-34 mm; greater than 35-40 mm suggests MCT displacement) and must be differentiated from hypertelorism (increased bony interorbital distance, which is not correctable by soft tissue surgery). Nasal dorsal depression produces a saddle nose deformity with loss of nasal projection. Bilateral periorbital ecchymosis ("raccoon eyes") is typical. Epiphora results from lacrimal system disruption. CSF rhinorrhea occurs with cribriform plate or posterior ethmoidal fracture. Subcutaneous emphysema comes from air in the ethmoidal or nasal sinuses. The bowstring test is performed by placing lateral traction on the lower eyelid -- if the MCT is intact, the medial canthal angle resists lateral pull; if disrupted, the entire lower lid moves laterally (positive test). Bimanual examination involves placing a hemostat or instrument into the nose and palpating the medial orbital rim externally to assess for mobility and crepitus of the central fragment.

Diagnosis

Clinical Tests

The intercanthal distance is measured and compared to the interpupillary distance (ICD should be approximately half of IPD). The bowstring test assesses MCT integrity. Bimanual palpation assesses central fragment mobility and comminution. Visual acuity and ophthalmic examination rule out globe injury.

Imaging

CT face (axial, coronal, sagittal) with 3D reconstruction is essential. It evaluates central fragment integrity and MCT insertion, assesses the degree of comminution, evaluates medial orbital walls, ethmoid sinuses, and cribriform plate, identifies associated fractures (frontal sinus, orbital floor, Le Fort), and detects pneumocephalus indicating skull base communication. 3D reconstruction aids surgical planning and classification.

Management

Goals

The goals are to restore medial canthal position (correct telecanthus), restore nasal dorsal projection and contour, repair medial orbital walls, address lacrimal system injuries, and manage CSF leak if present.

Surgical Approach

The coronal incision is the gold standard for bilateral NOE fractures, providing wide exposure of the entire upper midface, nasal root, and medial orbits. The Lynch incision (medial orbital) provides direct access to the medial orbital wall and may be used for limited unilateral injuries. Existing lacerations are utilized when possible. A transconjunctival incision provides supplementary access for the medial orbital wall and floor.

Type I Management

The central fragment is reduced with open reduction and fixed with miniplates at stable bone margins (nasomaxillary buttress, infraorbital rim). MCT position is restored by reducing the bone fragment, and transnasal wiring is usually not needed.

Type II Management

The comminuted fragments are reduced and the MCT-bearing piece is identified. Miniplate fixation of identifiable fragments is performed. Transnasal wiring may be needed for additional MCT support. Bone grafting addresses comminuted areas, with a cantilever bone graft for the nasal dorsum.

Type III Management

With severe comminution, the MCT cannot be fixed to bone fragments. Transnasal canthopexy passes a wire or suture through or around the MCT remnant, through the nasal bones or septum, and attaches it to the contralateral medial orbital wall. The wire is tightened to pull the MCT posteriorly, superiorly, and medially (the normal MCT vector). Overcorrection is essential because wire loosening leads to recurrent telecanthus. The wire is positioned posterior and superior to the lacrimal fossa, with the posterior lacrimal crest being the ideal fixation point. Medial orbital wall reconstruction uses bone graft or titanium mesh. Nasal dorsum reconstruction uses a cantilever bone graft (calvarial). An external bolster splint may be used to maintain MCT position during healing.

Transnasal Wiring Technique

The MCT or its remnant is identified on each side. A 28- or 30-gauge wire is passed through the MCT attachment. A hole is drilled through the contralateral medial orbital wall, posterior and superior to the lacrimal fossa. The wire is passed transversally through the nasal cavity and through the drill hole. The wire is tightened against the opposite side using a plate or washer as backing. Overcorrection by 2-3 mm is performed because the tendon will stretch and relax slightly. Alternatively, a microplate-and-screw system can be used for MCT fixation.

Nasal Dorsum Reconstruction

Loss of nasal projection is common in NOE fractures. Primary bone grafting with a cantilever calvarial bone graft extends from the nasion to the nasal tip. This may be performed at the time of NOE repair or as a secondary procedure. The soft tissue envelope must be adequate to support the graft.

Lacrimal System Management

Nasolacrimal duct patency is assessed. If disrupted, silicone stent placement (Crawford tubes) is performed through the canaliculi and nasolacrimal duct, with stents maintained for 3-6 months. Dacryocystorhinostomy (DCR) is performed if chronic obstruction develops.

<image>Intraoperative photograph showing transnasal canthopexy for a Type III NOE fracture with the wire passed through the medial canthal tendon remnant, traversing the nasal cavity, and secured to the contralateral medial orbital wall with a miniplate backing, demonstrating the overcorrected medial canthal position</image>

Complications

Persistent telecanthus is the most common complication, resulting from inadequate MCT repositioning or wire/suture loosening. Saddle nose deformity occurs from inadequate nasal dorsal reconstruction. Epiphora results from lacrimal system obstruction and may require DCR. Persistent CSF leak may require a lumbar drain or surgical repair. Meningitis occurs from intracranial communication. Enophthalmos results from medial orbital wall or floor deficiency. Nasal obstruction comes from mucosal scarring or septal deviation. Visible scarring from Lynch incisions is a concern, making coronal incisions preferred. Frontal sinusitis or mucocele can develop if the NFOT is obstructed.

Clinical Pearls

Telecanthus is the hallmark of NOE fractures, and the intercanthal distance should always be measured in any patient with midface trauma involving the nasal root. The bowstring test is simple and invaluable for differentiating an intact MCT from a disrupted one. Type III NOE fractures are the most difficult to correct and have the highest failure rate, so the transnasal canthopexy should be overcorrected. The MCT must be repositioned posteriorly and superiorly, not just medially; fixing it only medially results in a rounded medial canthal angle and persistent telecanthus. Nasal dorsum depression is the "forgotten deformity" in NOE fracture management, and dorsal augmentation should always be planned in comminuted injuries. CSF rhinorrhea in NOE fractures usually resolves with conservative measures (head elevation, avoidance of straining), but persistent leak beyond 5-7 days may require surgical repair or a lumbar drain. Secondary correction of telecanthus is extremely difficult, so it is essential to get it right the first time. A coronal approach provides the best exposure for bilateral NOE fractures and should be the standard when wide access is needed.

References

• Markowitz BL, et al. Management of the medial canthal tendon in nasoethmoid orbital fractures: the importance of the central fragment in classification and treatment. Plast Reconstr Surg. 1991.
• Manson PN. Facial fractures. In: Mathes SJ, ed. Plastic Surgery. 2006.
• Papadopoulos H, Salib NK. Management of naso-orbital-ethmoid fractures. Oral Maxillofac Surg Clin North Am. 2009.
• Herford AS, et al. Management of naso-orbito-ethmoid fractures. Oral Maxillofac Surg Clin North Am. 2013.
• Wei JJ, et al. Naso-orbito-ethmoid fractures: a review of 30 cases. Ann Plast Surg. 2015.
• Ellis E, Zide MF. Surgical Approaches to the Facial Skeleton. Lippincott Williams & Wilkins. 2006.

Read this lecture as Markdown