FP03-7. FIXATION OF THE STAPES FOOTPLATE IN CHILDREN. A CLINICAL AND TEMPORAL BONE HISTOPATHOLOGICAL STUDY

Edgar Bachor (SRH Zentralklinikum Suhl gGmbH, Germany), Tino Just (University of Rostock, Germany), Charles Wright (Southwestern Medical Center, USA), Hans Pau (University of Rostock, Germany), Collin Karmody (New England Medical Center, Boston, USA)

 

Objective: To clarify the anatomical characteristics, etiology and surgical outcomes relating to fixation of the stapes footplate in children.

Study design: Retrospective case review and, four-center histopathological study of temporal bones.

Setting/Patients: Tertiary referral center. We reviewed charts and histological specimens from 12 children, ages 7–13, who underwent surgery for footplate fixation. We also studied stapes footplates in 288 temporal bones from 181 children ranging from newborn (20.-44. weeks of gestation) to 13 years of age.

Main outcome measure: Anomalies of the stapes footplate in children.

Results: The average age of diagnosis of hearing loss was 6.6 years. Criteria for a diagnosis of otosclerosis were progression of a conductive hearing loss and an intraoperative finding of fixation of the anterior stapediovestibular joint in 5 patients. In contrast, a nonhomogeneous, thickened, fixed footplate and the absence of an annular ligament were indicators of congenital fixation in 6 children. In one child there was neither new bone from the otic capsule nor any obvious otosclerotic foci. In the temporal bone study, 17 of 181 (9.4%) children had anomalies of the stapes footplates with ankylosis in 4 (2.2%). In two subjects (1.1%) there was an otosclerotic focus not in contact with the stapes footplate.

Conclusions: Children below the age of 6 years with various congenital anomalies are more likely to have congenital footplate fixation, which will present intraoperatively as a thickened footplate with a partial or absent annular ligament. Children older than 6 years with progressive conductive hearing loss are more likely to have otosclerosis, which presents as fixation of the anterior stapediovestibular joint. The difference in surgical outcomes is probably related to different degrees of footplate pathology.

 

* Contact person email: ebmail@web.de