Unilateral conductive hearing loss (UCHL) in the presence of an intact tympanic membrane represents a diagnostic challenge in otologic practice. In the absence of middle ear effusion or tympanic membrane pathology, stapes fixation secondary to otosclerosis is often considered the most probable diagnosis. However, although otosclerosis is traditionally regarded as a bilateral disease, clinical presentation may be unilateral due to asymmetric disease progression or subclinical contralateral involvement. Other etiologies, including congenital ossicular anomalies, ossicular discontinuity, tympanosclerosis without tympanic membrane involvement, or oval window abnormalities, may mimic otosclerosis both clinically and audiologically. Consequently, exploratory tympanotomy remains the gold standard for definitive diagnosis, allowing direct assessment of ossicular chain mobility and confirmation of stapes fixation. Correlating preoperative clinical suspicion with intraoperative findings is therefore essential to better define the true causes of unilateral conductive hearing loss with an intact tympanic membrane.

Inclusion Criteria:

• unilateral conductive hearing loss or mixed HL with intact Tympanic Membrane
• Average Airborne Gap Above 20 decibels Exclusion Criteria
• Sensorineural hearing loss
• Chronic otitis media
• TM perforation
• Previous ear surgery

Individual participant data will not be shared due to institutional ethical restrictions and the retrospective nature of the study. The dataset contains potentially identifiable clinical and surgical information. De-identified aggregated data may be made available upon reasonable request to the corresponding author, subject to institutional review and approval.