Pre Op PTA & HRCT as prediction of ossicular chain status among CSOM patients: An Observational Study

Abstract

Background: Chronic Otitis Media (COM) is a prevalent condition associated with varying degrees of hearing loss, often due to ossicular chain damage. Pure Tone Audiometry (PTA) is routinely used to assess hearing impairment; however, its correlation with intraoperative ossicular status remains crucial for preoperative planning. Aim: To evaluate the correlation between Pure Tone Audiometry findings and ossicular chain status in patients with Chronic Otitis Media. Materials and Methods: A prospective observational study was conducted on 183 patients diagnosed with COM. Preoperative PTA was performed to assess hearing thresholds and type of hearing loss. Intraoperative findings regarding ossicular integrity were recorded during tympanoplasty or mastoid surgery. Statistical correlation was analyzed between PTA findings and ossicular status. Results: Among 183 patients, 62.3% had intact ossicular chain, while 37.7% showed ossicular discontinuity. Overall ossicles status was normal among 59(52.7%) mild CHLM 36(32.1%) moderate CHL patients and 8(7.1%) among Moderately Severe CHL. Eroded among 9(8.0%) Moderate CHL patients. There was a statistically highly significant difference found in ossicle status in CT according to severity of PTA among mucosal ear patients. (P=0.001) Ossicular erosion was significantly higher in unsafe COM compared to safe COM, indicating the aggressive nature of cholesteatoma-related disease.  There was a statistically significant difference found in ossicles status between squamosal and mucosal patients. (P<0.05). Increasing air-bone gap (ABG) was significantly associated with ossicular erosion (p < 0.001). Patients with ABG >40 dB predominantly had multiple ossicular involvement. Conclusion: PTA findings, particularly air-bone gap, serve as a reliable predictor of ossicular status in COM. This correlation aids in surgical planning and patient counseling.