Nonotosclerotic Ankylosis of the Stapedial Footplate*

Histopathology of Nonotosclerotic Stapes Fixations

“…At this time, the correct differential diagnosis of otosclerosis and nonotosclerotic stapes fixations is based on histologic analysis of ankylotic stapes footplates removed during stapes surgery because clinical diagnostic methods (high-resolution computed tomography, magnetic resonance imaging, and audiometry) give uncertain results (1,3,5,17). One third of stapes fixations are nonotosclerotic stapes ankylosis, which means that one third of stapes surgeries is performed for nonotosclerotic stapes ankylosis (1,3).…”

“…One third of stapes fixations are nonotosclerotic stapes ankylosis, which means that one third of stapes surgeries is performed for nonotosclerotic stapes ankylosis (1,3). To simplify the definition of stapes ankylosis, we should point out that otosclerosis is stapes fixation, but stapes fixation can be other diseases than otosclerosis.…”

“…These substances could flow into the perilymph and change the electromotility of outer hair cells, which may explain the sensorineural hearing loss in otosclerosis (24). The long-term prognosis and surgical/functional outcomes of nonotosclerotic stapes fixations are theoretically better than those of otosclerosis because there is no otic capsule involvement and consecutive sensorineural hearing loss (1,3,6,15). Our hypothesis that differences between the long-term prognosis of otosclerosis and nonotosclerotic stapes fixations are associated with the histopathology and depend on the pericochlear bone involvement need to be confirmed by further prospective audiologic examinations.…”

“…Patients with ankylotic stapes are characterized by normal otoscopic findings and conductive-or mixed-type hearing loss as general symptoms (3,4). Clinical diagnosis of stapes fixation does not correspond to the histologic diagnosis of otosclerosis (1,3,5).…”

“…It should be established that clinical and demographic features of otosclerosis have, in fact, reference to stapes ankylosis. Otosclerosis and nonotosclerotic stapes ankylosis cannot be distinguished clinically (1,3,13). Differential diagnosis of different types of stapes fixations is based on postoperative histologic analysis of the removed stapes footplates in spite of the helpful preoperative clinical examinations (otoscopy, audiometry, high-resolution computed tomography, magnetic resonance imaging, measles serology) (1,18,19).…”