Surgery for congenital anomalies of the middle ear with mobile stapes.

In a series of 104 patients with congenital middle ear anomalies operated on from 1964 to 1986, 27 cases were found in which the stapes footplate was mobile and the conductive deafness was due to an anomaly in the remaining part of the ossicular chain. In 8 cases the middle ear anomaly was caused by discontinuity of the ossicular chain owing to congenital malformation. In the other 19 ears, epitympanic fixation of the ossicular chain was observed, whether or not in combination with malformation of the stapes, incus or malleus. Ossicular chain reconstruction produced an improvement of at least 15 dB in 6 of the first 8 cases with discontinuity of the ossicular chain. The mean gain was 31 dB. Epitympanotomy with exposure of the fixed ossicle and if necessary ossicular chain reconstruction led to an improvement of at least 15 dB in 12 of the 19 ears, with a mean gain of 28 dB.