Malleus-to-footplate prosthetic interposition: Experience with 265 patients

Absence of the long process of the incus with or without absence of the sta pes head accounts for more than 80% of ossicular discontinuities. Total or partial replacement prostheses, made of various materials, are interposed t o restore the transfer function of the middle ear. To simplify ossicular re construction, reduce operative times and costs, improve functional outcomes , and avoid the risk of infections, we have adopted, during the past 10 yea rs, a technique that makes use of a personally designed alloplastic prosthe tic device. The prosthesis connects the malleus to the footplate, even in t he presence of the stapes superstructure. This malleus-to-footplate prosthe sis consists in a plastipore-coated steel piston and hydroxyapatite head, c omplete with a groove. The groove is placed beneath the malleus neck after dissection of the tensor tympani tendon and the shaft of the piston on the footplate. Two hundred ninety primary ossiculoplasties with the malleus-to- footplate prostheses were performed in 265 patients from 1986 to 1995 in th e ENT Department of the University of Verona. The average postoperative air -bone gap at 0.5 to 3 kHz was 11 dB at 1 year and 14 dB at 5 years. These o utcomes are significantly better than those personally obtained previously with ossicular or alloplastic prostheses. No extrusions occurred. The struc tural characteristics of the malleus-to-footplate prosthesis endow the pros thesis with a high degree of biocompatibility and stability and optimal sou nd-transfer function. The rationale for this particular ossiculoplasty proc edure is discussed.