Laryngeal contusion and fracture

Although the larynx is composed primarily of hyaline cartilages that are attached to each other and surrounding structures by muscular or fibrous tissues, direct trauma to the neck area can result in a contusion and fracture of the larynx, or more precisely, a fracture of the laryngeal cartilages. [ 1 ]

Epidemiology

In laryngeal injuries, the incidence of cartilage fractures ranges from 1% to 67%. And in terms of the frequency of causes of death in patients with head and neck injuries, laryngeal cartilage fractures are second only to craniocerebral injuries.

According to foreign traumatologists, about 50% of all laryngeal injuries are caused by injuries to the cricoid cartilage.

Some studies provide data on the main causes of fracture of the thyroid cartilage of the larynx: 15.4% of cases are due to car accidents (collisions); 7.7% - falls from a height; 5% - attacks with blunt force to the head and neck; 3.8% - cut wounds; 2.6% - gunshot wounds; about 1.3% - explosions.

According to statistics from pathologists and forensic experts, in 34% of cases of suicidal hanging and manual/ligature strangulation, victims have a fracture of the thyroid cartilage of the larynx, and in two-thirds of cases, fractures of the laryngeal-hyoid bone. [ 2 ], [ 3 ], [ 4 ]

Causes contusion and fracture of the larynx

Causes that lead to contusion and fracture of the larynx: a blow to the throat with a fist or any blunt object during a physical attack or during sports, strangulation, blunt/penetrating injuries to the cervical spine in road traffic accidents. [ 5 ] For example, during head-on or rear-end collisions, the neck (joints, muscles and ligaments) is often severely stretched when it is quickly bent forward and then backward, causing a whiplash injury. Contusion and fracture also occur when a person riding a bicycle or motorcycle hits a taut wire, rope or tree branch with an exposed neck. [ 6 ]

A fracture can result from penetrating trauma from gunshot or knife wounds to the neck. [ 7 ], [ 8 ]

Among the iatrogenic causes of laryngeal fractures are bronchoscopy, laryngoscopy, emergency intubation or percutaneous tracheostomy, as well as tracheal intubation with the installation of an endotracheal tube for anesthesia during surgery.

Read also – Damage (injuries) of the larynx and trachea – Causes and pathogenesis

Risk factors

Possible risk factors for laryngeal fracture following minor trauma or due to non-traumatic causes include weakness of the laryngeal cartilage – from previous trauma, use of systemic corticosteroids, congenital abnormalities of the cartilage, decreased bone mineral density – where even a minor force to the neck, such as coughing or sneezing, can result in a fracture of the laryngeal cartilage.

In addition, the risk of laryngeal cartilage fracture is increased by impaired calcium metabolism and cartilage calcification, which is observed not only in many elderly people, but also in those who undergo continuous hemodialysis and in patients with diabetes mellitus or hyperparathyroidism.

Pathogenesis

The larynx is located in the front of the neck – at the level of the C3-C6 vertebrae and connects the lower part of the pharynx with the trachea; its skeleton consists of six cartilages (three single and three paired). [ 9 ], [ 10 ]

The single thyroid cartilage (cartilago thyroidea), which supports the anterior part of the larynx and forms the cervical protrusion (Adam's apple) in men, is connected by ligaments to the hyoid bone (os hyoideum) and another single cartilage, the cricoid cartilage (cartilago cricoidea), which is attached to the upper part of the trachea and forms the lower wall of the larynx. [ 11 ], [ 12 ], [ 13 ]

The cartilages of the larynx – the thyroid, cricoid, and then the paired arytenoid cartilages (cartilago arytaenoidea) – begin to ossify after 18-20 years, and with age the degree of physiological ossification increases. And it is these cartilages that are affected by a laryngeal fracture. [ 14 ]

Its pathogenesis is caused by compression of cartilage in the direction of the cervical spine. Under the influence of a directly applied force, internal tissue tension occurs, and when their ability to withstand this force is insufficient, a cartilage fracture occurs, which manifests itself in the form of a rupture. [ 15 ], [ 16 ]

Symptoms contusion and fracture of the larynx

The main symptoms of a laryngeal contusion are: neck pain, including odynophagia – pain when swallowing; swelling of the neck; difficulty with phonation (pronouncing sounds) and hoarseness; stridor (noisy breathing); hematoma (bruise) on the neck. Dyspnea, endolaryngeal hematomas and cough with bloody foam are possible.

Neck pain and hoarseness are the first signs that occur immediately after a traumatic episode that leads to a fracture of the laryngeal cartilage. Also, air accumulation in the subcutaneous tissue may be observed - subcutaneous emphysema.

In addition, symptoms of a laryngeal fracture include more severe swelling of the neck and hematoma; with a mild fracture, damage to the inner mucous membrane of the larynx is insignificant, the cartilage may be exposed, but without displacement.

Fracture of the thyroid cartilage of the larynx usually results from blunt trauma and immediately presents with significant swelling and airway compromise with loss of consciousness due to hypoxia.

A more severe fracture results in diffuse edema and significant alteration of the mucosa; exposed cartilage may be displaced, vocal cord mobility may be impaired or ruptured; persistent dyspnea and often respiratory distress develop due to narrowing of the airway.

One of the most severe fractures is considered to be a fracture of the cricoid cartilage as a result of a strong direct blow, which in almost half of the cases leads to a rupture (partial or complete) of its connection with the trachea - a cricotracheal or laryngotracheal rupture - with a violation of the integrity of the first tracheal ring, displacement of cartilage fragments, massive alteration of the mucous membrane and retraction of the trachea into the upper mediastinum.

In many cases, a simultaneous fracture of the thyroid and cricoid cartilages is observed.

See also - Symptoms of Larynx and Trachea Injuries

Complications and consequences

Traumatic injuries to the larynx in the form of contusion and fracture are accompanied by complications and have consequences, depending on the severity and etiology of the injury.

Thus, damage to the mucous membrane of the larynx - as it heals - can be complicated by the formation of scars and the development of cicatricial stenosis. In addition, there may be a loss of voice due to paralysis or paresis of the vocal cords; swallowing disorders are possible.

Laryngeal fractures are potentially life-threatening because they result in severe airway problems. For example, due to asphyxia caused by tracheal obstruction, the mortality rate for cricoid fractures with laryngotracheal avulsion or laryngeal rupture is approximately 40%. [ 17 ], [ 18 ]

Diagnostics contusion and fracture of the larynx

Diagnosis begins with anamnesis and examination of patients with recording of existing symptoms.

The most important role in identifying laryngeal injuries is played by visualization of its structures, and instrumental diagnostics include: X-ray of the larynx and pharynx, endoscopic laryngoscopy, computed tomography and MRI of the cervicothoracic spine. [ 19 ], [ 20 ], [ 21 ]

Also read – Damage (injuries) of the larynx and trachea – Diagnostics

Differential diagnosis

Differential diagnostics are carried out with all diseases and conditions whose symptoms include shortness of breath, stridor or vocal cord dysfunction.

Treatment contusion and fracture of the larynx

Laryngeal fracture can lead to life-threatening airway obstruction, so patients with suspected laryngeal fracture should be given urgent first aid - oral intubation with oxygen via mask or tracheostomy - to maintain airway patency and ensure breathing. In critical situations, emergency cricothyrotomy (cricoconicotomy) is used, vertically incising the skin, subcutaneous tissues, thyrohyoid membrane (between the upper edge of the thyroid cartilage and the hyoid bone) and cricothyroid ligament. [ 22 ]

Useful information in the article – Damage (injuries) of the larynx and trachea – Treatment

In case of laryngeal cartilage fractures, with the exception of mild cases (when voice rest, inhalation of corticosteroids, painkillers and other drugs are prescribed), surgical treatment is performed - planned surgical intervention on the respiratory tract.

Possible surgeries: open reduction and internal fixation of laryngeal skeletal fractures; restoration of laryngeal mucosal tears (endoscopic plastic surgery); installation of an endolaryngeal stent to maintain the integrity of the larynx; complex plastic surgery of the larynx and trachea (including fixation of the fracture with a cartilaginous autograft or mini-plate). [ 23 ], [ 24 ], [ 25 ] Other materials used for internal fixation after reduction of the laryngeal fracture are steel wire and titanium plates. [ 26 ], [ 27 ], [ 28 ]

Prevention

The issue of preventing laryngeal cartilage fractures can be partially resolved only in relation to the outcomes of car accidents. And it is not only a matter of following traffic rules and speed limits, but also the mandatory use of seat belts and/or the presence of airbags in the vehicle.

Forecast

Given the fact that the overall mortality rate from laryngeal injuries, in particular cartilage fractures, is 2-15% (according to other data, almost 18%), the prognosis is not favorable in all cases. And although laryngeal contusion and fracture can affect speech, swallowing and breathing functions, one should keep in mind the potential for death. In 62-85% of cases, a favorable voice outcome is noted, while favorable outcomes for airway patency are achieved in 76-97% of cases. [ 29 ]