Missing stapes and stapes-replacing prosthesis.

Our study of 205 ears with missing stapes, secondary to some type of chronic ear disease, showed that only 40% of such ears are suitable for ossiculoplasty. The remaining 60% are unsuitable because of a fixed footplate, severe atelectasis, hearing better than 25 dB (these patients do not need the operation), or poor discrimination. A new stapes replacement prosthesis (SRP), which we term Tabor, is described for use where indicated. The prosthesis has two parts: The lower part (or base) is made of a broad inorganic, biocompatible material (Teflon). This part fits and covers most of the footplate, ensuring maximal stability. The upper part of the prosthesis is made of autograft or homograft bone--usually a malleus head--the contact of which with the drum prevents extrusion. In twelve out of fourteen ears insertion of this prosthesis was successful; the average postoperative air conduction went from 56 dB to 29 dB, leaving an average air-bone gap of 16 dB. The bone conduction also improved, from an average of 20 dB to 13 dB.