The effect of stapes surgery on high frequency hearing in patients with otosclerosis.

OBJECTIVE: To assess the effect of stapedectomy on high frequency hearing. STUDY
DESIGN: A retrospective, one-group, pretest-posttest case review was performed of the audiometric data of patients who underwent stapedectomy at a tertiary referral center. PATIENTS: Thirty-eight patients (40 ears) with primary uncomplicated surgery were selected. Twenty-two of the patients were older than 40 years. Preoperative and postoperative audiograms were analyzed.
RESULTS: Preoperative and postoperative audiograms exhibited a down-sloping configuration toward the high frequencies. Surgery resulted in a significant improvement (p < 0.05) from 500 to 4000 Hz in air conduction and 500 to 2000 Hz in bone conduction. Analysis of variance showed that age had no bearing on preoperative audiometric results (p < 0.05) for air conduction, bone conduction, and the air bone gap. Postoperatively, younger patients' 4000 to 8000 Hz (air conduction) and 4000 Hz (bone conduction) were better than those of the older patients (p < 0.05), but the high frequency range was still poorer than age-matched controls in the younger patients.
CONCLUSION: Stapedectomy resulted in significant closure of the air bone gap between 500 to 4000 Hz, but failed to influence hearing above 4000 Hz. Age appears to be an important variable; poorer results in the high frequency range were seen in the older patients who underwent stapes surgery. These findings, together with the residual postoperative hearing loss in the high frequency range in young patients, may reflect disease-specific injury resulting from cochlear otosclerosis.