Hearing recovery following large and small fenestra stapes surgery for otosclerosis.

Fifty-five ear of 49 patients with otosclerosis were operated on with either large fenestra stapes (stapedectomy; SDE) or small fenestra stapes (stapedectomy; STO) surgery. Pre-operative average hearing levels for the speech frequency ranges (0.5, 1, 2 kHz) were 56.1 dBHL for SDE and 61.0 dBHL for STO. These improved to 39.0 dBHL and 35.0 dBHL. Statistically, significant hearing recovery was obtained for a frequency range from 0.125 to 2 kHz for SDE and from 0.125 to 4 kHz for STO (p < 0.05, Dunnett's multiple variance test). The degree of post-operative hearing improvement for STO was significantly higher at 0.5, 2 and 8 kHz than that for SDE (p < 0.05, Student's t-test). A pre-operative speech discrimination score of 80% was obtained at 68.9 dB for SDE and at 76.0 dB for STO. These values improved to 56.1 dB and 49.5 dB post-operatively. Thus, it was proved that STO results in better hearing than SDE does.