Stapes-Pyramidal Fixation by a Bony Bar

A 26-year-old man presented to our clinic with a left progressive hearing loss of several years’ duration. His tympanic membrane appeared normal, and no significant otologic history was discovered. Pure-tone audiometry and tympanometry of the left ear showed a conductive hearing loss of 70 dB with an air-bone gap of 60 dB and a type AS tympanogram. Computed tomography (CT) of the temporal bones revealed no temporal bone anomalies. Exploratory tympanotomy revealed that a bony bar was extending from the pyramidal eminence to the posterior crus of the stapes, with involvement of the stapedius tendon, leading to stapes fixation (figure). The mobility of the footplate was normal. Therefore, resection of the bony bar and the ossified stapedius tendon was performed with a microdrill. The postoperative course was uneventful, and the air-bone gap had been reduced to 18 dB by the time of the 2-year follow-up. In isolated congenital ankylosis of the stapes, fixation of the footplate is by far most commonly encountered. Other congenital ankyloses include fixation of the suprastructure by a separate bony bridge to the pyramid or facial canal, elongation of pyramidal eminence, or ossification of the stapedial tendon.1 Ossification of the stapedius tendon giving rise to