Contusion and fracture of the larynx

Although the larynx consists mainly of hyaline cartilages that are attached to each other and surrounding structures by muscle or fibrous tissues, as a result of direct trauma to the neck area, a bruise and fracture of the larynx, more precisely, a fracture of the cartilage of the larynx, can result.[1]

Epidemiology

With injuries of the larynx, the frequency of fracture of its cartilage ranges from 1% to 67%. And in terms of the frequency of causes of death in patients with head and neck injuries, cartilage fracture of the larynx is in second place - after craniocerebral injuries.

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

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

According to the statistics of pathologists and forensic experts, in 34% of cases of suicidal hanging and manual/ligature strangulation, the 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 of the contusion and fracture of the larynx

Causes leading to bruising and fracture of the larynx: blow to the throat with a fist or any blunt object during a physical attack or during sports activities, strangulation, blunt / penetrating injuries of the cervical spine in road traffic accidents. [5]For example, during frontal or rear impact crashes, there is often a severe, sharp strain on the neck (joints, muscles, and ligaments) as it rapidly bends forward and then back, causing whiplash. Also, a bruise and fracture occurs when, while riding a bicycle or motorcycle, a person hits a stretched wire, rope or tree branch with an open neck.[6]

Penetrating trauma from gunshot or stab wounds to the neck can lead to a fracture.[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.

See also -  Damage (injury) of the larynx and trachea - Causes and pathogenesis

Risk factors

Possible risk factors for laryngeal fracture after minor trauma or non-traumatic causes include weakness of the larynx cartilage - from past trauma, use of systemic corticosteroids, congenital cartilage anomalies, decreased bone mineral density - when even a minor impact on the neck, such as when coughing or sneezing, can lead to a fracture of the cartilage of the larynx.

In addition, the risk of fracture of the cartilage of the larynx is increased in violation of calcium metabolism and calcification (calcification) of the cartilage, which is observed not only in many elderly people, but also in those who are constantly undergoing 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 - cricoid (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 - thyroid, cricoid, and then paired arytenoid cartilages (cartilago arytaenoidea) - after 18-20 years begin to ossify, and with age, the degree of physiological ossification increases. And it is these cartilages that affect the fracture of the larynx.[14]

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

Symptoms of the contusion and fracture of the larynx

The main symptoms of a bruised larynx: pain in the neck, including odynophagia - pain when swallowing; swelling of the neck; difficulty in phonation (pronunciation of sounds) and hoarseness; stridor (noisy breathing); hematoma (bruise) on the neck. Shortness of breath, 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 cartilage of the larynx. Also in the subcutaneous tissue may be observed accumulation of air - subcutaneous emphysema.

In addition, the symptoms of a laryngeal fracture are manifested by more severe swelling of the neck and hematoma; with a mild degree of fracture, damage to the internal mucous membrane of the larynx is insignificant, the cartilage can be exposed, but without displacement.

Fracture of the thyroid cartilage of the larynx is usually the result of blunt trauma and is immediately manifested by significant edema and airway obstruction with loss of consciousness due to hypoxia.

A more severe fracture leads to diffuse edema and significant mucosal alteration; the exposed cartilage may be displaced, the mobility of the vocal cords is impaired or ruptured; due to the narrowing of the airways, persistent shortness of breath develops, and often respiratory distress.

One of the most severe is 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 - cricotracheal or laryngotracheal detachment - with a violation of the integrity of the first tracheal ring, displacement of cartilage fragments, massive alteration mucous membrane and retraction of the trachea into the superior mediastinum.

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

See also -  Symptoms of injuries of the larynx and trachea

Complications and consequences

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

So, 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 loss of voice due to paralysis or paresis of the vocal cords; swallowing may be impaired.

Fractures of the larynx are potentially life-threatening as they lead to serious airway problems. For example, due to asphyxia caused by tracheal obstruction, the mortality rate for cricoid fractures with laryngotracheal avulsion or laryngeal rupture is about 40%.[17], [18]

Diagnostics of the contusion and fracture of the larynx

Diagnosis begins with anamnesis and examination of patients with the fixation of existing symptoms.

The most important role in identifying injuries of the larynx is played by the 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 (injury) of the larynx and trachea - Diagnosis

Differential diagnosis

Differential diagnosis is carried out with all diseases and conditions, the symptoms of which include shortness of breath, stridor, or dysfunction of the vocal cords.

Treatment of the contusion and fracture of the larynx

A fracture of the larynx can lead to life-threatening airway obstruction, so patients with a suspected fracture of the larynx should urgently receive first aid - oral intubation with oxygen through a mask or tracheostomy - to maintain a patent airway and ensure breathing. In critical situations, emergency cricothyroidotomy (cricoconicotomy) is resorted to, vertically dissecting the skin, subcutaneous tissues, the thyroid-sublingual membrane (between the upper edge of the thyroid cartilage and the hyoid bone) and the cricothyroid ligament.[22]

Useful information in the article -  Damage (injury) of the larynx and trachea - Treatment

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

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

Prevention

The issue of prevention of fractures of the cartilage of the larynx can be partially resolved only with respect to the outcomes of car accidents. And it's not just about obeying the rules of the road and the speed limit, but also about the mandatory use of seat belts and / or the presence of airbags in the vehicle.

Forecast

Considering the fact that the overall mortality from injuries of the larynx, in particular, cartilage fracture, is 2-15% (according to other sources, almost 18%), the prognosis is far from favorable in all cases. And although contusion and fracture of the larynx can affect the functions of speech, swallowing and breathing, one should keep in mind the potentially fatal outcome. 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]