Pharyngeal injuries with hyoid bone fractures: causes, symptoms, diagnosis, treatment

The hyoid bone is an unpaired bone formation of the neck skeleton. It is located in the middle of the neck, below and behind the chin and immediately above the thyroid cartilage. The hyoid bone is curved in a horseshoe shape, with its convexity facing forward and its concavity facing backward. It consists of a middle part (body) located with its major axis across the neck and two pairs of horns - small and large, with their apophyses directed backward. The hyoid bone develops from the fusion of the second visceral and first branchial arches. Imperfection of this embryogenetic process leads to some developmental anomalies of the hyoid bone with the preservation of its cartilaginous and bone remnants in the palatine tonsils and surrounding tissues. Ossification points in the body and large horns of the hyoid bone appear in the 8th-10th month of intrauterine life. In the small horns, these points appear only in the 1st or 2nd year of life. The fusion of individual parts of the hyoid bone is completed by the age of 30-40.

The hyoid bone is suspended directly from the skull by the stylohyoid ligaments and muscles of the same name, as well as the digastric muscles, which are attached to it on both sides. The hyoid bone is fixed to the lower jaw anteriorly by a group of muscles (geniohyoid and mylohyoid); these muscles participate in the movements of the lower jaw in the horizontal plane. The hyoid bone serves as an attachment point for the muscles of the tongue (hyoglossus, part of the fibers of the genioglossus, and the long upper and lower muscles of the tongue). Part of the pharyngeal muscles, such as the middle constrictor of the pharynx, finds a fulcrum on the hyoid bone. A number of muscles approach the hyoid bone from below; their contractions lead to the lowering of the bone and the larynx suspended from it (scapulohyoid, thyrohyoid, and sternohyoid muscles). All of the listed muscles maintain the hyoid bone in a stable median position; reciprocity and coordination of the function of these muscles is provided by innervation by fibers of the V, VII and XII pairs of cranial nerves, as well as from the cervical nerve plexus. Many functional disorders of the coordination of the action of these muscles and dysfunction of the pharynx arise due to organic lesions of these nerves and their centers, as well as various pathological influences on these centers of the overlying structures of the brain. When any of these nerves is damaged, the coordinated activity of the muscular apparatus of the hyoid bone is disrupted, which entails a change in the position of the tongue and soft palate, voice and speech, swallowing and chewing.

Symptoms of pharyngeal injuries with hyoid bone fractures. Hyoid bone fractures are rare and occur with blunt trauma to the submandibular region with direct mechanical impact on the body of the hyoid bone, sometimes they occur with hanging, strangulation and rarely - from the impact of muscle traction.

Clinically, a fresh fracture of the hyoid bone is manifested by severe pain during all acts accompanied by movement of the hyoid bone. At the site of the fracture there is a hematoma visible from the outside, and upon palpation - crepitus and mobility of fragments. In fractures of the hyoid bone with a rupture of the mucous membrane of the pharynx, severe bleeding from the mouth is observed, caused by damage to the branches of the lingual and superior thyroid arteries.

Treatment of pharyngeal injuries with hyoid bone fractures involves eliminating the displacement of fragments and immobilizing them. Reposition of fragments is achieved by palpation from the oral cavity and from the outside. Immobilization of the head and neck is achieved using a special cervical-shoulder corset (collar) or by applying a plaster "bed" to the neck and shoulders. In most cases, fragments can only be held in the correct position by surgical repositioning and suturing using an approach such as transverse sublingual pharyngotomy. Pharyngeal bleeding is stopped either by non-surgical methods (cold, activation of the blood coagulation system, pharyngeal tamponade after laryngeal intubation) or by ligation of the external carotid artery.

The prognosis in the first hours after the injury is questionable due to the possibility of asphyxia, and in the case of a ruptured throat, significant blood loss. Death often occurs before the arrival of emergency specialized care or on the way to a medical facility. If there are signs of asphyxia and bleeding at the scene, tracheal intubation and pharyngeal tamponade should be performed and only after these manipulations should the victim be taken to a specialized department.

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