A case of fracture of the stapes superstructure with an intact incudostapedial joint caused by indirect trauma

Fracture of the stapes following head injury is thought to be clinically less common than displacement of the incus or disarticulation of the incudostapedial joint. We present a case of traumatic fracture of the stapes due to an indirect force without dislocation of the incudostapedial joint. A 52-year-old male was referred to our hospital complaining of hearing loss on the left side four weeks after a traffic accident that had led to the patient sustaining multiple intracranial injuries with disturbance of consciousness. He recovered with conservative treatment and subsequently became aware of hearing loss in the left ear. A pure-tone audiogram showed a 70-dBHL conductive hearing loss with a 40-dB air-bone gap. Temporal bone computed tomography (CT) revealed disarticulation of the incudomalleolar joint and displacement of the stapes. After exploratory tympanotomy, we found disarticulation of the incudomalleolar joint, and fracture of both the stapedial crura, however, the incudostapedial joint and the footplate of the stapes were intact. Six months after type IV tympanoplasty, the patient achieved air-bone gap closure to within 15 dB. In the present case, the incudostapedial joint was preserved, while the patient had sustained considerably forceful head injury that caused multiple intracranial injuries and dislocation of the ossicles, which is a rare form in indirect trauma of the ossicular chain. In addition, multiplanar reconstruction images of temporal bone CT allowed us to accurately diagnose the pathology of the ossicular chain in the patient.