Incidence

Nasal bones are the most commonly fractured bones in the face. While reports estimate the annual incidence of nasal fractures in the United States as 52,000, the actual number may be higher for a variety of reasons, including the fact that severely traumatized patients with life-threatening injuries may concurrently present with nasal fractures that go unrecognized. The mechanism of injury is usually blunt trauma and can be attributed to assault, motor vehicle accidents, a fall, or a sports-related injury. Previous nasal surgery may have an impact on the incidence of acute nasal fracture ; a patient who undergoes rhinoplasty is at an increased risk of nasal fracture, particularly within the first year following the rhinoplasty procedure.

Nasal fractures in the pediatric population may be overlooked. The pediatric nose is mostly cartilaginous and the nasal bones are small; therefore, the pediatric nose is softer and more compliant, therefore being less likely to sustain displacement than the adult nose when fractured. Despite these attributes, pediatric nasal fractures do occur. A review of the pediatric facial fractures in the National Trauma Data Bank demonstrated a 30.2% incidence of nasal fractures in children and adolescent trauma patients (aged 0 to 18 years). The most common mechanisms of injury are motor vehicle collisions, violence, falls, and sports-related injuries. Another potential cause of nasal fracture in the pediatric population is birth trauma. Birth trauma, from intrauterine forces, breech delivery, or forceps-assisted delivery, may result in congenital deviation of the nasal septum. Although these deviations can be treated easily, expeditiously, and usually without complication in the neonatal period, the identification of a deviated septum can be overlooked. The pediatric nose is very susceptible to septal hematoma following blunt trauma. Unfortunately, childhood nasal trauma is often underappreciated and nasal fracture and/or septal injury is overlooked, resulting in external and internal nasal deformities in adulthood.

Mechanism of Injury

Murray’s seminal work in detailing the pathophysiology of nasal bone fractures in fresh cadaver specimens provided valuable insight into the mechanism of injury for nasal trauma. Nasal fractures are most commonly due to a lateral force; this results in two fracture lines running parallel on the ipsilateral thin nasal bone along the dorsum, meeting at the junction of the thick and thin bones ( Figure 38-1 ). In this type of injury, the nose may appear deviated due to the depression of the unilateral bony fragment.

The nasal bones. The nasal bony vault is pyramidal in shape and forms the upper third of the nose. The nasal bony vault consists of the paired nasal bones and the ascending frontal process of the maxilla. The nasal bones are thicker and more dense superiorly and are progressively thinner inferiorly. There is a transition zone of relatively thin bone along the frontal processes of the maxilla from the piriform aperture to the radix along the lateral nasal wall.

A frontal force must be of greater magnitude to produce a nasal fracture because the nasal bones are buttressed by the frontal process of the maxilla, the nasal spine, and the perpendicular plate of the ethmoid. The resultant injury includes not only a nasal bone fracture (which may be comminuted) but also a C-shaped fracture in the septum extending from just beneath the dorsum of the nose, inferiorly and posteriorly through the perpendicular plate of the ethomid and curving anteriorly to the inferior cartilaginous septum near the maxillary crest and the angle of the vomer. Frequently, the inferior end of the septum becomes dislodged from its groove and is deflected obliquely into the nasal cavity ( Figure 38-2 ). As a result, the ala and nostril on the deflected side can become widened, while the opposite side can become flattened and narrowed.

The nasal septum and patterns of septal fractures. The septal (aka quadrangular cartilage) articulates with the anterior nasal spine caudally, the perpendicular plate of the ethmoid posteriorly, and the vomer inferiorly; the vomer articulates with the maxillary and palatine crests. The septal cartilage typically rests along a groove at the midline; this is known as the vomerine groove. The most common septal fracture is along this junction between the vomerine groove and quadrangular cartilage. A high-velocity injury or frontal impact can result in a more extensive septal fracture through the thin central region of the septal cartilage and extending to the bony cartilaginous junction.

A high-impact frontal force injury to the nose, such as that sustained during a motor vehicle collision, may produce comminuted or compound nasal fractures. If a patient sustains this type of injury, one must rule out a nasal orbital ethmoid (NOE) complex fracture after the cervical spine, skull, and ophthalmic injuries are cleared. Signs of NOE complex fractures include telecanthus, epiphora, periorbital emphysema, clear rhinorrhea secondary to cerebrospinal fluid leak, and a flattened nasofrontal root. Surgeons should have a low threshold for requesting a noncontrast computed tomography (CT) scan of the facial skeleton if the slightest clinical suspicion for an orbital or facial fracture arises. Further work-up and management of NOE injuries are beyond the scope of this chapter.

Diagnosis

Identification of a nasal fracture is primarily a clinical diagnosis and plain radiographs are rarely, if ever, necessary. Patients may experience epistaxis, edema, ecchymosis, and nasal obstruction. Upon palpation, tenderness, crepitus, and step-off deformities may be appreciated. An obvious deformity may be appreciated, such as a conspicuous concavity or convexity of the nasal bones resulting in a twisted nose appearance. In the acute setting, evidence of nasal deformity may be hidden secondary to the masquerading effects of edema.

Avulsion of the upper lateral cartilage attachments may also result in a concave appearance of the middle third of the nose. The cephalic portion of the upper lateral cartilage is attached to the caudal border of the nasal bone. The medial portion of the upper lateral cartilage is attached to the dorsal cartilaginous septum; this attachment constitutes the internal nasal valve and has been described as a 10- to 15-degree angle on intranasal examination. Placement of a cotton-tipped applicator in the region of the internal nasal valve with subsequent improvement in nasal airway obstruction confirms the diagnosis of internal nasal valve collapse. Closed reduction of the fractured nasal bone may reapproximate the avulsed upper lateral cartilage to the caudal border of the nasal bone. However, avulsion of the upper lateral cartilage from the dorsal cartilaginous septum may require placement of a spreader graft to address the concavity of the middle third of the nose as well as improve nasal function by reconstituting the internal nasal valve.

Intranasal examination should be performed after decongesting the nasal cavities. Topical oxymetazoline is effective and, when mixed with 4% topical lidocaine, can achieve both decongestion and anesthesia. Intranasal examination is performed to evaluate the status of the septum and identify mucosal injuries. If a bulge is appreciated along the septum, this may signify a septal hematoma. If a septal hematoma is suspected, a helpful maneuver is to palpate the intranasal bulge with a cotton-tipped applicator and, if compressible, a fine needle aspiration can be performed. In the pediatric patient, the nose tends to buckle and twist rather than fracture. As such, there is a higher incidence of separation of the perichondrium from the septal cartilage and subsequent potential for hematoma formation. Digital photodocumentation of the resulting nasal deformity can be obtained for the medical record.