Traumatic Ossicle Extrusion into the External Auditory Canal

Abstract

We report a rare case of incus dislocation into the external auditory canal following a head injury. The patient was a 35-year-old man who presented to the surgical emergency unit with a head injury that he had sustained during a traffic accident. An x-ray of the skull detected a longitudinal fracture of the right temporal bone. The ENT examination revealed the presence of a bony structure and a blood clot in the right external auditory canal. Computed tomography identified a disruption of the ossicular chain, with an incus-like bony shadow in the external canal. The wide opening of the fracture line and the impact of the accident were believed to have pushed the incus through the fracture and into the external canal. The patient was successfully treated with exploratory tympanotomy and ossiculoplasty.

Sports-related head injury as a cause of ossicular trauma

“…While damage through an infection or damage to the tympanic membrane is one of the first thoughts for damage to the auditory system, it seems to be overlooked that damage can easily afflict the ossicles of the middle ear. 1,2 It is important to understand that although these are three bones within the middle ear cavity, these bones are miniscule in comparison to other bones of the body. The auditory ossicles are a chain of small bones in the middle ear that transmit sound from the outer ear to the inner ear through mechanical vibration.…”

“…Therefore, the lack of support makes is easy to dislocate the ossicular chain. 2 While general damage to the ossicular chain can be congenital or from infections, dislocation of the ossicular chain mainly occurs from trauma, particularly head injuries of the temporal lobe. 2 The temporal bone houses much of the auditory system, particularly the middle ear cavity.…”

“…2 While general damage to the ossicular chain can be congenital or from infections, dislocation of the ossicular chain mainly occurs from trauma, particularly head injuries of the temporal lobe. 2 The temporal bone houses much of the auditory system, particularly the middle ear cavity. This means that any blunt trauma to the side of the head, where the temporal bone is located, runs the risk of bringing dislocation to the ossicles.…”

“…A damage to the ossicular chain is called ossicular chain dislocation and is also referred to as ossicular discontinuity or ossicular disarticulation. 1,2,4,7,8 The typical locations for ossicular dislocation are, primarily, the incudostapedial joint and, rarely, the incudomalleolar joint. 3,8 While it is easy to think simplify the damage to the ossicular chain as simply a dislocation or a subluxation, fractures to the ossicles can also occur due the sustained head trauma from the sport.…”

“…3,8 While it is easy to think simplify the damage to the ossicular chain as simply a dislocation or a subluxation, fractures to the ossicles can also occur due the sustained head trauma from the sport. 1,2,4,5,7,8 The typical location for ossicular fractures are at the stapes crura and the incus. 3,7 However, fractures of the ossicles are uncommon in comparison to dislocation, but fractures are possible due to the intensity of the blunt sport trauma.…”