Teaching Case

A 49-year-old female presented with a 2-week persistency of dysphonia and odynophagia after an anterior neck blunt trauma by a surfboard, in the Pacific Ocean. A neck X-ray had locally been performed and was considered normal. She denied dyspnoea. Her physical examination, including indirect laryngoscopy, and past history were unremarkable.

Neck CT without intravenous contrast revealed incompletely ossified larynx cartilages. Two solution of continuity lines were found in each side of the antero-lateral cricoid ring, causing posterior deviation of the detached anterior fragment. Additionally, subtle anterior and inferior dislocation of the left arytenoid cartilage could be seen. 3D reformations also showed a horizontal discontinuity at the base of the right superior horn of the thyroid cartilage. Oedema, haematoma and extraluminal air were not found.

Background

The larynx is a complex anatomical structure of the infrahyoid visceral space of the neck, connecting the pharynx above/posteriorly to the trachea below. It has key roles in breathing and phonation. It is composed of a complex cartilaginous framework that includes the thyroid cartilage, the cricoid cartilage, the epiglottis, and paired arytenoid, corniculate, and cuneiform cartilages, linked together by muscles, ligaments, and covered by mucosa. Larynx traumatic injuries are very rare, due to the protection provided by the anterior/lateral neck muscles, the sternum and the mandible, and most frequently result from direct blow [1-3].

Clinical Perspective

Causes of larynx blunt trauma include motor vehicle accidents, assaults, attempts of hanging and sports. They are not usually reported in surfers [4]. Symptoms at diagnosis can vary from life-threatening stridor and dyspnoea to neck oedema, bruises, pain, odynophagia, dysphonia, and subcutaneous emphysema [1-3,5].

Physical examination is sometimes compromised due to soft tissue oedema or hematoma and may miss laryngeal lesions. As such, imaging plays a critical role in the diagnosis [1].

Assessment of the airway patency, cartilage framework integrity, and evaluation of the adjacent soft tissues are fundamental data the requesting physician needs to plan patient treatment.

Imaging Perspective

Multidetector CT is the imaging modality of choice to diagnose laryngeal trauma. Sagittal, coronal and oblique reformations, together with 3D reconstructions, and readings in soft tissue and bone windows are often needed to achieve the correct diagnosis. Due to incomplete and asymmetric ossification of the larynx cartilages, different orientation of fracture lines, and multiplicity of fracture sites, diagnosis is often difficult, mainly in young patients [1,2,6].

Fractures are more common in the thyroid cartilage.

As in other ring-like structures, the cricoid usually fractures in at least two sites [1].

Cricoarytenoid complete and incomplete dislocations are rare, usually caused by trauma, and present with dysphonia/hoarseness and neck pain. The arytenoids can luxate anteriorly or posteriorly. The position of the arytenoid cartilages must be carefully analysed as a deviation can be easily missed [7].

The extension of larynx trauma is made by ENT observation together with CT analysis.

Outcome

Larynx trauma is potentially life-threatening. An early and accurate imaging diagnosis is crucial to allow adequate therapy planning. Therapeutic options include conservative management and surgery. The decision is made based on clinical criteria together with the injury classification according to the Schaefer Classification: Types I and II can be treated conservatively, whereas surgical treatment may be considered for types 3 to 5 [8].

Take Home Message / Teaching Points

Larynx trauma is a potentially life-threatening situation.

CT is the imaging modality of choice in the initial evaluation.

Imaging multiplanar reformations and 3D reconstructions, together with a high degree of suspicion are needed to make the correct diagnosis.

Key-imaging findings are cartilage fracture lines, cartilage dislocations, soft tissues oedema and/or haematoma, and subcutaneous emphysema.

Written informed patient consent for publication has been obtained.