Neck hyperflexion causing isolated thyroid cartilage fracture--a case report.

Isolated thyroid cartilage fracture is very rare, and most cartilage fractures are caused by direct impact to the laryngotracheal complex of the neck. Isolated thyroid cartilage fracture caused by hyperflexion of the neck has not been reported before. We present a case where an unrestrained front seat car passenger struck his forehead on the windshield during a motor vehicle accident. Direct impact of his forehead with sudden and forceful flexion of his neck caused isolated thyroid cartilage fracture without direct impact to the neck. Therefore, injury to the thyroid cartilage should be kept in the list of detailed evaluation with high index of suspicion in patients presenting with trauma mechanism possibly causing neck hyperflexion, even without signs of direct neck trauma.