Tympanoplasty in partial defects of the stapedial arch.

A defective stapedial arch was found among 690 operated patients in 46 ears (6-7 per cent). Most often it was the stapedial head or anterior limb which was absent. The problems and results of ossiculoplasty on a defective stapes are analyzed. Classical interposition of the incudal body on top of a defective stapes did not afford satisfactory results, as the incus had to be placed asymmetrically on top of the stapedial remnant, with a risk of fixation and tilting of the graft. Better results were obtained by interposition of the short process of the incus on the footplate in a way which gives the incus contact also with the remaining parts of the stapedial arch. If the neck and head of the stapes are absent, it is suggested that the ossicles be shaped in relation to the defect in such a way that contact between the stapedial remnant and the malleus will be stable and the risk of secondary fixation minimal. If there are partial defects of the stapedial limbs the columella should be in contact with the footplate as well as with the remaining parts of the limbs.