Case 1—endolaryngeal hematoma without detectable fracture (Schaefer group 1)
A 24-year-old male presented with neck swelling without signs of respiratory distress after a traumatic blunt neck injury. There was swelling of the anterior neck without palpable crepitus. Airway ultrasound showed disruption of the air–mucosal interface suggesting endolaryngeal disruption (Fig. 1b). CT scan confirmed the diagnosis of endolaryngeal disruption without cartilaginous fracture. The patient was conservatively managed and discharged well on the third day.
Case 2—undisplaced thyroid cartilage fracture (Schaefer group 2)
A 66-year-old motorcyclist, was injured in a collision with a van. He presented with mild neck pain, difficulty in breathing, hoarseness, dysphagia and odynophagia. He had stridor, and his neck was swollen and tender with subcutaneous emphysema.
Airway ultrasound using a 15-MHz linear transducer found discontinuity of the anterior cortex of thyroid cartilage with minimal surrounding tissue edema, consistent with Schaefer group 2 (Fig. 2c). CT scan confirmed the ultrasound findings, showing a defect in the posterolateral wall of the trachea and the esophagus, with fracture of the right anterior lamina of the thyroid cartilage and superior cornu of the left thyroid cartilage (Fig. 2d).
He was immediately intubated and was started on intravenous dexamethasone to reduce inflammation and edema, a proton pump inhibitor to prevent reflux and laryngeal irritation, nebulized adrenaline and a prophylactic antibiotic in the emergency department. The patient was managed conservatively and was discharged well from intensive care unit on the fifth day post trauma.
Case 3—displaced thyroid cartilage fracture (Schaefer group 3)
A 28-year-old male martial art athlete was kicked by his opponent and sustained a blow to the anterior part of the neck. He complained of pain, dysphagia and hoarseness. There was an abrasion to the anterior part of his neck, which was tender to palpation with localized crepitus.
Bedside airway ultrasound revealed a displaced fracture of the thyroid cartilage, disruption of anterior cortex of thyroid cartilage with surrounding mixed echogenicity denoting endolaryngeal edema (Fig. 3a and Additional file 1: Video S1) and paralyzed right vocal cord (Fig. 3e), consistent with Schaefer group 3.
Direct visualization using a flexible fibreoptic scope revealed an edematous and medially deviated right arytenoid with paralyzed and erythematous right vocal cord. He was intubated and intravenous dexamethasone, proton pump inhibitor, nebulized adrenaline and prophylactic antibiotic were initiated early in the emergency department. The patient was sent for CT neck after stabilization, which showed a defect in the posterolateral wall of the trachea with a displaced fracture of right anterior lamina of thyroid cartilage and superior cornu of left thyroid cartilage, consistent with Schaefer group 3 (Fig. 3b), and that found on bedside ultrasound. The patient was stable throughout his entire hospitalization after open surgical repair and was allowed home on day nine with outpatient follow up.
Case 4—displaced thyroid cartilage fracture (Schaefer group 3)
A 35-year-old male lorry driver hit his neck against the steering wheel when he thrown forwards during a head-on collision. He presented with neck pain, severe swelling over the whole anterior region of the neck, stridor, hypoxia and a compromised airway. The patient was immediately intubated and ventilated.
Focused airway ultrasound showed disruption of the air–mucosal interface, a displaced thyroid cartilage fracture with formation of endolaryngeal hematoma and a cricoid cartilage fracture (Fig. 4b). He was treated as Schaefer group 3 and was started on intravenous dexamethasone, proton pump inhibitor, nebulized adrenaline, prophylactic antibiotic and open surgical repair was planned.
CT scan revealed a defect in the posterolateral wall of the trachea with a displaced fracture of the left anterior lamina of thyroid cartilage and hematoma surrounding the thyroid and cricoid cartilages. This confirmed the classification and injury details categorized under Schaefer group 3, which correlated with that of ultrasound assessment. Hospital stay was uneventful, and he went home after 2 weeks, to be reviewed in the outpatient department.