The Value of HRCT in Stapes Fixations Corresponding to Hearing Thresholds and Histologic Findings

Objective: To estimate the correlations between high-resolution computed tomography (HRCT) scans, preoperative audiometric findings and histopathologic results in stapes ankylosis. Study Design: Retrospective case review. Setting: Tertiary referral center. Patients: A total of 57 patients with stapes ankylosis, who underwent unilateral stapedectomies were analyzed. Interventions: Diagnostic and therapeutic. Main Outcome Measures: Preoperative HRCT examinations were performed in all cases. Findings of HRCT were categorized according to Marshall's grading system. Preoperative air-bone gaps (ABGs) and bone conduction (BC) thresholds were determined. Stapes footplates removed surgically were processed using hematoxylin and eosin staining. Results: Active otosclerosis (n = 29) was demonstrated by HRCT with a sensitivity of 76.31%, whereas its sensitivity to establish inactive otosclerosis (n = 13, 61.9%) and nonotosclerotic stapes fixations (n = 15, 51.7%) was much lower. Nonotosclerotic stapes fixations were characterized by pure conductive hearing loss that was not associated with HRCT findings. HRCT grades showed statistically significant association with BC levels at the averages of 0.5-1-2 kHz frequencies in the group of ears with inactive otosclerosis, exclusively (p < 0.05). Conclusion: HRCT is a reliable imaging method in the preoperative diagnosis of different types of stapes fixations. Imaging findings should be evaluated together with clinical history and audiometric data for obtaining as precise diagnosis for stapes fixation as possible.