Non-Traumatic Thyroid Cartilage Fracture from Sudden Neck Motion: Clinical Insights

Introduction

Laryngeal fractures are rare, comprising less than 1% of all traumatic fractures [1]. The estimated incidence is 1 in 30 000 to 1 in 40 000 trauma admissions [2]. The larynx is supported by several cartilaginous structures, with the thyroid cartilage being the largest and most prominent anterior cartilage of the laryngeal framework [3]. The laryngeal skeleton includes the thyroid, cricoid, and arytenoid cartilages, connected by membranes and ligaments [3]. The thyroid cartilage is most commonly involved in laryngeal fractures due to its prominent position anteriorly and relative lack of mobility compared with the cricoid cartilage [4].

Blunt laryngeal trauma typically results from direct injury to the anterior neck, as can occur in motor vehicle collisions, sports injuries, manual strangulation, or blows to the neck [5]. The sudden application of blunt force leads to a rapid rise in intralaryngeal pressure, resulting in rupture of the laryngeal cartilages [5]. Well-described mechanisms leading to laryngeal fractures include dashboard injuries, clothesline injuries during sports, and choke holds [6]. Intubation and anesthesia-related maneuvers have also been reported to cause laryngeal cartilage fractures on rare occasions [3].

Spontaneous, non-traumatic fractures of the laryngeal cartilages have also been described in the literature. A systematic review by Khalid et al identified several causes of non-traumatic laryngeal fractures, including vigorous coughing (most common), sneezing, vomiting, and straining during physical activity. These mechanisms typically involve sudden increases in laryngeal pressure [7,8]. Proposed mechanisms include increased age-related ossification and calcification of the laryngeal cartilages, resulting in brittle bones prone to fracture [9]. Connective tissue disorders and laryngeal pathology have also been suggested as predisposing factors [10].

Prompt and accurate diagnosis of laryngeal fractures is crucial due to their potential for rapid airway compromise and long-term voice impairment. Misdiagnosis or delayed treatment can lead to life-threatening airway obstruction, chronic voice disorders, and swallowing difficulties [11]. The management of these injuries requires a delicate balance between airway preservation and optimization of long-term laryngeal function [1]. Early recognition allows for timely intervention, which may range from conservative management to urgent surgical repair, depending on the severity of the injury [12]. Furthermore, appropriate management can significantly improve outcomes, reducing the risk of complications such as laryngeal stenosis, chronic aspiration, and permanent dysphonia.

While spontaneous, non-traumatic fractures of the laryngeal cartilages have been documented, they are typically associated with forceful coughing, sneezing, or Valsalva maneuvers [13]. These actions cause sudden increases in intraluminal pressure, potentially leading to cartilage fracture, especially in older individuals with calcified laryngeal structures. However, our case presents a unique mechanism of thyroid cartilage fracture resulting from sudden neck movement without direct trauma or common precipitating factors such as coughing or sneezing. This unique etiology expands our understanding of potential causes for laryngeal fractures and highlights the need for clinicians to consider this diagnosis even in the absence of direct trauma or typical precipitating events.

This report describes the case of a 42-year-old man presenting with hoarseness and pain when swallowing and a diagnosis of non-traumatic thyroid cartilage fracture.

Case Report

A 42-year-old man with no past medical history presented with 5 days of progressively worsening neck pain and hoarseness. The symptoms began during driving when the patient made a sudden, sharp leftward turning movement of his head in the horizontal plane. This rapid rotational movement, not accompanied by any significant neck flexion or extension, resulted in the patient feeling a distinct ‘pop’ in his neck, immediately followed by pain and discomfort. He did not experience any trauma, collision, or episodes of coughing/sneezing around the time of injury.

The patient’s medical history was unremarkable, with no prior neck issues, respiratory problems, or endocrine disorders. He denied any history of trauma to the neck region. The patient reported leading an active lifestyle but no contact sports. He was a non-smoker and consumed alcohol occasionally. The patient reported no recent changes in his daily routine or unusual physical activities before the incident.

On presentation, he was afebrile with normal vital signs. A physical exam showed midline neck tenderness without swelling or ecchymosis. Flexible fiberoptic laryngoscopy revealed normal vocal cord mobility with mild thickening and erythema of the left vocal cord. Given the unusual mechanism of injury and the absence of external trauma, we pursued a comprehensive diagnostic approach. Initial neck ultrasound showed air surrounding the laryngeal cartilage, raising concerns for a more significant injury. This finding prompted us to perform a computed tomography (CT) scan of the neck to assess the extent of laryngeal injury and to rule out other potential cervical pathologies. The CT was crucial in identifying the non-displaced thyroid cartilage fracture and confirming the presence of soft tissue emphysema (Figure 1). Based on the Schaefer classification [14], this was a grade II laryngeal fracture.

The presence of free air in the neck, coupled with the unclear mechanism of injury, led us to perform a barium swallow study despite the lack of specific esophageal symptoms. This decision was made to exclude potential injuries to the hypopharynx or esophagus, particularly to rule out perforation, which could have serious consequences if missed, given the presence of cervical emphysema. The barium swallow study was unremarkable, reassuring against any concomitant pharyngeal or esophageal injury.

The patient was admitted for airway monitoring and started on intravenous antibiotics. Repeat flexible laryngoscopy on day 2 of admission showed stable vocal cord function and improved erythema. He remained afebrile and hemodynamically stable with no progression of pain or dysphonia. He was discharged home on hospital day 3 on a 7-day course of oral antibiotics. At 1-week and 1-month follow-up visits, the patient’s examination was completely normal, with no hoarseness, pain, or evidence of emphysema.

Discussion

This case report provides several important clinical lessons. First, it demonstrates that thyroid cartilage fracture can occur following sudden neck movement alone, without direct trauma or common precipitating factors such as coughing or sneezing. Second, it emphasizes the importance of considering laryngeal injury in patients presenting with neck pain and voice changes, even when the mechanism seems trivial. Third, it shows that careful imaging and endoscopic evaluation are essential for accurate diagnosis in such cases. Finally, it demonstrates that conservative management can be successful in stable patients with non-displaced fractures, even when classified as grade II injuries.

Most reports of laryngeal fractures involve significant blunt neck trauma [5,6]. Spontaneous, non-traumatic fractures have been linked to forceful coughing or sneezing [14]. This case report presents an isolated laryngeal fracture after sharp neck movement without direct neck trauma, coughing, sneezing, or other precipitating events.

While spontaneous laryngeal fractures have been documented in the literature, as reviewed by Khalid et al, our case presents a distinct mechanism involving sudden neck rotation [8]. Fenig et al reported a case of thyroid cartilage fracture in a 68-year-old man following a severe coughing fit [13]. Similarly, Beato Martínez et al described a thyroid cartilage fracture in a 30-year-old woman after a powerful sneeze [15]. These cases, along with an early report by Quinlan of a fracture during a sneeze [16], align with the more commonly recognized mechanisms of spontaneous laryngeal injury involving sudden increases in intraluminal pressure. Of particular relevance to our case, Lurin et al recently reported a case of spontaneous longitudinal rupture of the thyroid cartilage in a 56-year-old man without any apparent trauma or excessive physical effort [17]. This case, like ours, highlights the possibility of laryngeal injury occurring without typical precipitating factors. Our case stands out as it involves a rapid rotational movement of the neck, further expanding our understanding of the potential causes of laryngeal fractures. These reports collectively underscore the need for clinicians to consider this diagnosis even in the absence of obvious trauma or common precipitating events.

The mechanism by which a sudden neck movement could cause a thyroid cartilage fracture without direct trauma warrants further consideration. One possible explanation involves the complex biomechanics of the neck and larynx during rapid rotational movements. While providing structure to the larynx, the thyroid cartilage is also subject to forces exerted by the attached muscles and ligaments. An abrupt imbalance in these forces could occur during a sudden, sharp rotational movement. The sternothyroid and thyrohyoid muscles, which attach to the thyroid cartilage, might exert sudden, opposing tensions during rapid neck rotation [18]. This could potentially create a shearing force across the cartilage structure.

Additionally, the rapid movement might cause a momentary increase in intraluminal pressure within the larynx, similar to what occurs during coughing or sneezing but localized due to the rotational nature of the movement [5]. In older individuals, age-related calcification of the laryngeal cartilages could make them more susceptible to fracture under such circumstances [19]. While these are speculative mechanisms, they provide a framework for understanding how a non-traumatic, rapid neck movement could result in cartilage fracture.

Despite the unique mechanism of injury, the diagnosis and conservative management parallel published cases [1,14]. The patient recovered well without the need for surgical fixation or tracheostomy, even though most grade II laryngeal fractures require more aggressive airway intervention [2]. This highlights the importance of tailoring treatment to clinical stability.

While our case was managed conservatively, it’s important to note that surgical intervention is sometimes necessary for laryngeal fractures. Surgical management is typically indicated in cases with severe displacement, exposed cartilage, vocal cord immobility, or airway compromise [11,20]. The goals of surgical treatment include maintaining airway patency, preserving voice quality, and preventing aspiration [3]. Techniques may include open reduction and internal fixation of fracture fragments [12]. In some cases, endoscopic approaches have also been described [21]. The decision between conservative and surgical management should be based on the severity of the injury, the patient’s overall condition, and the expertise of the treating team.

This case underscores the importance for clinicians, particularly in emergency and primary care settings, to maintain a high index of suspicion for laryngeal injury, even in patients presenting with seemingly minor neck complaints or unusual mechanisms of injury. Early recognition and appropriate management of these rare but potentially severe injuries can significantly impact patient outcomes and prevent long-term complications such as chronic voice changes or airway issues.

Conclusions

This report has presented a rare case of non-traumatic thyroid cartilage fracture following sudden neck motion. The case highlights the importance of careful history and imaging of the structures of the neck, particularly in patients presenting with voice changes, even without apparent trauma. Furthermore, it supports the efficacy of conservative management in stable, non-displaced laryngeal fractures. This case expands our understanding of potential causes of laryngeal fractures and emphasizes the importance of thorough evaluation in seemingly minor neck injuries.