Bone and air conduction after stapedectomy.

UNLABELLED: Otosclerosis causes loss of air conduction (AC) but also bone conduction (BC) may be deteriorated. It is reported that also BC may improve after surgical treatment of otosclerosis. The investigation was carried out in a group of 50 patients treated due to otosclerosis in our institution. The group included 34 women and 16 men, at the age 24 to 55 years. Pure-tone audiometry for bone and air conduction threshold was performed in all the patients. Hearing tests were carried out before and 2-4 months after the operation by the same technician Partial. Only patients with air-bone gap closure were included in the study. Stapedectomy was performed under local anaesthesia. RESULTS: Significant improvement of AC was obtained after stapedectomy. There was also significant improvement of BC at all the frequencies examined of 6-12 dB and it depended on BC threshold before surgery. In the group of 37 patients with BC threshold before surgery > or = 30 dB a significant improvement of BC after stapedectomy developed. In the group of 14 patients with BC threshold before surgery < 30 dB the change of BC after stapedectomy was not significant. Successful stapedectomy improves bone conduction. It means that in patients with otosclerosis there is a reversible BC pseudo hearing loss and it is related to BC threshold before the operation.