Primary stapes surgery in patients with otosclerosis: prediction of postoperative outcome.

OBJECTIVES: To evaluate the audiometric results of primary stapes surgery in patients with otosclerosis and to determine predictors of a postoperative air-bone gap (ABG) of 10 dB or less and a postoperative gain in air conduction (AC) exceeding 20 dB.

DESIGN: Retrospective cohort study.

SETTING: Tertiary referral center in Utrecht, the Netherlands.

PATIENTS: Nine hundred thirty-nine patients with otosclerosis who underwent primary stapes surgery between January 1, 1982, and March 1, 2009.

INTERVENTION: Primary stapes surgery.

MAIN OUTCOME MEASURES: Preoperative and postoperative audiometric results were compared. Logistic regression analyses were performed to evaluate which factors (ie, sex, age at surgery, bilateral otosclerosis, and preoperative 4-frequency [0.5, 1, 2, and 4 kHz] ABG, AC, or bone conduction) independently contributed to the prediction of a postoperative ABG of 10 dB or less and a postoperative gain in AC exceeding 20 dB.

RESULTS: A total of 72.1% of patients had a postoperative ABG of 10 dB or less, and 93.8% of patients had a postoperative ABG of 20 dB or less. Age at surgery and preoperative ABG and AC were independent prognostic determinants. A patient older than 40 years with a preoperative ABG of 30 dB or less has a 77.6% chance of achieving a postoperative ABG of 10 dB or less. A patient with a preoperative AC exceeding 50 dB and a preoperative ABG exceeding 30 dB has an 86.2% chance of achieving a postoperative gain in AC exceeding 20 dB.

CONCLUSIONS: Following primary stapes surgery, a postoperative ABG of 10 dB or less and a postoperative gain in AC exceeding 20 dB may be predicted with accuracies of 62.1% and 80.1%, respectively. Clinicians can use this information to inform patients more explicitly about expected postoperative audiometric results.