Nonotosclerotic ankylosis of the stapedial footplate.

A woman with a long history of chronic otitis media had a stapedectomy after a surgical diagnosis of otosclerosis. In the histologic study of the temporal bones, done after her death four years later, the main portion of the stapes footplate was present but fractured and no otosclerosis was present. New celluluar bone which simulated otosclerosis filled the anterior oval window niche and was continuous with the middle ear surface of the footplate fragments. The new bone extended anteriorly to overlie a tympanosclerotic focus and inferiorly was continuous with the periosteum of the middle ear. At least part of the new bone formation occurred after stapedectomy. This may explain the poor long-term results frequently encountered when a stapedectomy is done on patients with tympanosclerotic fixation of the stapes footplate.