Stapedectomy at the Singapore General Hospital--use of functional hearing analysis

The results of stapedectomy surgery performed in Singapore General Hospital covering a period of over two years are reviewed. The diagnostic importance of selected clinical features and investigative procedures in otosclerosis is studied. The post-operative hearing status of twenty-six cases of primary stapedectomy is analysed using traditional audiometric and modern functional methods. Seventeen patients (65.4%) achieved closure of air-bone gap to less than 10 dB while the overall mean hearing gain was 28.6 dB. Using the Glasgow Plot parameter, 73.1% showed significant benefit from surgery, whilst the corresponding figure using the Belfast Rule of Thumb assessment technique was 57.7%. The validity of the foregoing evaluation techniques is compared. Different operative techniques, including variations in fenestra size and method of oval window seal showed statistically similar results. The scarcity of stapedectomy cases poses problems in the training of future specialists.