Carhart notch in otosclerosis: relevant finding or pure curiosity?

Objective: To assess the prevalence of Carhart notch (CN) using three distinct audiometric criteria, explore its association with radiological staging and assess its predictive value for postoperative audiometric outcomes following stapes surgery. Study Design: Retrospective observational. Methods: Adult patients who underwent stapes surgery for otosclerosis (2017- 2024) were included. Pre and postoperative audiometric data were analyzed, applying three distinct CN definitions. Radiological staging followed Symons-Fanning and Veillon classifications. Statistical analysis assessed associations between Carhart notch, imaging findings and surgical outcomes. Results: A total of 108 ears from 99 patients met the inclusion criteria. CN prevalence varied from 46% to 66.7%, depending on classification criteria. No significant association was found between CN and imaging staging or surgical outcomes. Conclusion: Variability in CN definition compromises its detection and standardization. The lack of correlation with radiological findings and clinical outcomes questions its practical relevance in otosclerosis evaluation.