Different diseases without exact histopathologic classification can cause stapes ankylosis.
Otosclerosis is a complex bone remodeling disorder of the otic capsule due to persisting measles virus infection and consecutive inflammatory reaction. In fact, clinical and demographic features of otosclerosis have reference to stapes ankylosis. In the clinical practice, otosclerosis and stapes ankylosis are incorrect synonyms.
Nonotosclerotic stapes footplates (n = 284) removed during stapedectomy were analyzed histologically. Otosclerosis was excluded during the histologic preselection (n = 437). Total RNA was extracted, and measles virus-specific reverse-transcriptase-polymerase chain reaction was performed.
Nonotosclerotic stapes ankylosis was associated with total absence of measles virus RNA. Six main types of nonotosclerotic stapes fixations could be distinguished histologically: annular calcification (n = 152; 53.5%), globular fibrosis (n = 49; 17.25%), lymphocytic infiltration (n = 31; 10.9%), hemosiderosis (n = 22; 7.75%), granulomas (n = 17; 6%) and amyloidosis (n = 13; 4.6%). Fragmentation of nonotosclerotic stapes footplates was infrequent (7%) during stapes surgery. Only 1 floating footplate (0.35%) was reported.
Two thirds of nonotosclerotic stapes footplates represented complete pathologic bone remodeling. Unlike otosclerosis, nonotosclerotic stapes fixations were characterized by basic histopathologic findings without organ specificity that can also be identified in case of different diseases. Prevalence of nonotosclerotic stapes ankylosis is approximately 30 to 40% among stapes fixation cases. The long-term prognosis and surgical considerations theoretically differ from those of otosclerosis.
Departments of *Otolaryngology Head and Neck Surgery and †Anatomy, Histology and Embryology, University Medical School of Debrecen, Debrecen; ‡ENT Department, Bajcsy-Zsilinszky Hospital, Budapest; §Department of Otolaryngology Head and Neck Surgery, University Medical School of Pécs, Pécs; and ∥Department of Otolaryngology Head and Neck Surgery, University Medical School of Szeged, Szeged, Hungary
Address correspondence and reprint requests to Tamás Karosi, M.D., Ph.D., Department of Otorhinolaryngology Head and Neck Surgery, University Medical School of Debrecen, Debrecen, Nagyerdei Krt. 98. H-4032, Hungary; E-mail: email@example.com, firstname.lastname@example.org
This work was supported by Grants PD75371 and OTKA K63743 from the Hungarian Scientific Research Fund (OTKA) and Grant DEOEC MEC 17/2008 from the Mecenatúra Fund of Debrecen University.