The histopathologic findings in the temporal bones of four patients with otosclerosis who had stapes operations, each according to a different surgical technique, are discussed. The four surgical methods employed included: 1) stapes interposition with a vein graft; 2) polyethylene strut over a vein graft; 3) fenestration of an obliterated oval window with a teflon piston; and 4) wire prosthesis over a remaining, shattered footplate. The first, third and fourth method provided a very satisfactory seal for the oval window. The polyethylene strut, on the other hand, protruded deeply into the vestibule and was about to perforate through the thinned vein graft. In the three remaining patients, the vestibular end of the prostheses was in fairly good alignment with the level or the oval window. Within the middle ear cavity all prostheses were invested in a thin coat of endothelial cells and connective tissue. Whereas the ring of the teflon piston prosthesis caused no bony atrophy, the stainless steel wire had induced a localized deossification at its site of attachment on the incus. The third and fourth cases disclosed some adhesions in the perilymphatic space around the oval window. All temporal bones revealed no injury to, or rupture of the utricle or saccule.
