Surgical attempts to restore hearing in otosclerotic deafness were at first direct in their approach to the stapediovestibular articulation in the oval window (Kessel,1 Miot,2 Blake,3 and Jack4). The approach was then transferred by most otologists to an indirect, or detour, route to the perilymph space by fenestration of the horizontal semicircular canal (Holmgren,5 Sourdille,6 and Lempert7). The recent reports of Rosen8 have redirected our efforts to the oval window in an attempt to overcome some of the acoustic deficits and technical problems of the indirect, or fenestration, procedure.
There are major distinctions between the surgical concepts of fenestration and stapes mobilization surgery. Basic acoustic and anatomicopathologic differences exist. Since the fenestration operation is a detour procedure and one in which the approach to the perilymphatic vestibule is usually remote from the otosclerotic focus, it can be regarded as a precise operative