[Middle ear implants (Tübingen type) of Al2O3 ceramics. Follow-up to 6 years after surgery].

Since 1980 we have been using Al2O3 ceramic implants in some reconstructions of the ossicular chain. We began interposing a small autologous cartilage perichondrium disk between implants of this type and the ear-drum after having observed the first cases of imminent extrusion and of extrusion. Thus about half the implants in our first follow-up study. in 1984, were shielded by a cartilage disk; in 1984 91 patients (108 ears) were examined. 64 of the same patients (66 ears) consented to be re-examined in a second follow-up study in 1986. Of the 66 Al2O3 ceramic implants in the smaller sampling 43 had a cartilage overlay, and 23 did not. The implants without a cartilage overlay had been in situ for 3 to 6 years, and on average for 59 months; those with a cartilage overlay had been in situ for 3 to 6 years, and on average for 59 months; those with a cartilage overlay had been in situ for 2 to 5 years, and on average for 39 months. Both studies show the feasibility of markedly reducing the risk of imminent extrusions and extrusions, which occur when the cavum tympanum is poorly ventilated and the ear-drum retracts. The extrusion rates for Al2O3 middle-ear implants with and without a cartilage overlay were 5% and 16% respectively from 1980 to 1986. The great majority of ears examined showed a residual air-bone-gap of 0 to 20 dB in the frequency range between 0.5 and 2 kHz. Our audiometric results were essentially the same in 1984 and 1986.(ABSTRACT TRUNCATED AT 250 WORDS)