MANIPULATING THE MOBILE STAPES DURING TYMPANOPLASTY - THE RISK OF STAPEDIAL LUXATION

Manipulating the mobile stapes is a central procedure during tympanopl asty, i.e., mounting a prosthesis onto the stapedial head or dissectin g cholesteatoma matrix off the oval window niche. An excessive displac ement of the stapedial suprastructure as caused by these manipulations with hand-held instruments might result in a rupture of the annular l igament. Bacteria invading through this perilymphatic fistula threaten the inner ear. In experiments with temporal bones, the author investi gated the rupture mechanisms of the annular ligament with definite sta pedial manipulations. Leaks, which became detectable by exerting press ure on the inner ear fluid, occur only when all suspension fibers are completely ruptured. Further clinical aspects with different direction s of stapedial manipulations are demonstrated.