Clinical investigation of otosclerosis

We studied 192 ears with clinical otosclerosis operated on from 1984 to 2006, focusing on the clinical features and hearing improvement, causes of treatment failure, and the relationship between the computed tomographic (CT) and audiometric findings. The patients ranged in age from 14 to 73 years old (mean: 45.7 years). Small-fenestra stapedectomy was performed on 177 ears, partial stapedectomy on 11 ears, and total stapedectomy on 4 ears. The prosthesis used was the Shuknecht-type Teflon wire piston in all cases; the 4.25 mm teflon wire piston was used for 101 (52.6%) ears. The hearing outcomes were satisfactory in 188 (97.9%) ears, based on the criteria proposed by the Otological Society of Japan (2000). No hearing improvement was achieved in 4 ears. Long-term hearing failure was noted in 3 ears; the suspected causes were displacement of the prosthesis and the presence of fibrotic tissue around the prosthesis. We found otospongiotic lesions in 62% of the cases. No significant differences were observed in the bone conduction thresholds between the ears with lesions around the cochlea and those with lesions anterior to the vestibule. (author)