INJURY RISK RELATED TO THE HELMET STRAP: MANDIBLE AND HYOID BONE FRACTURES WITH A HYOEPIGLOTTIC LIGAMENT LESION

Hyoid bone fractures are rare (0.002% of all fractures) and most result from strangulation or hanging. Other causes are direct trauma, mostly traffic accidents, sports injuries, gunshots, and induced vomiting. The diagnosis is often difficult, especially when associated with other soft tissue injuries or fractures, which may seem more worthy of treatment. Only one hyoid bone fracture caused by a helmet strap in a traffic accident has been reported. The case we present is unusual. A 65-year-old male motorcycle accident victim was brought to the emergency department of our hospital. On arrival, he was awake and oriented. He had significant bleeding from the mouth and was in respiratory distress; he also had neck swelling and subcutaneous crepitus without significant pain (spontaneous or provoked by pressure). Physical examination of the neck was difficult because of the presence of an orthopedic collar; he reported painful swallowing. The skin on the chin was lacerated. No nosebleed or other skin injury was present. He had dysphonia, with a guttural, helium-like voice. The patient wore superior and inferior removable dental prostheses: the inferior one had been broken and lost during the crash, while the superior one had been damaged, but not dislodged. After removing it, no mucosal wounds were seen in the oral cavity and no blood was seen draining from the pharynx posteriorly. Because bleeding from the nose and mouth were excluded, an ENT surgeon and anesthesiologist were consulted with regard to the respiratory distress, and the patient was intubated. Subsequently, fibre optic endoscopy was used to evaluate the upper aero-digestive tract (UADT): a large laceration was found in the glossoepiglottic region, with a hyoepiglottic ligament lesion and subsequent posterior epiglottis collapse on the glottic plane (Fig. 1). As the patient was stable and could be monitored, computed tomography (CT) was performed and showed fractures of the mandibular symphysis and left condyle, thyroid cartilage, and hyoid bone bilaterally, with disarticulation of the hyoid corpus from the greater horns (Fig. 2). Significant subcutaneous emphysema of the neck was also seen. A maxillofacial surgeon was asked to evaluate the mandibular fractures. The physical examination also revealed left wrist trauma; standard X-rays showed dislocation of the lunate bone and a temporary brace was applied to immobilise the wrist.