The Metal Prosthesis for Stapes Ankylosis

Introduction Early oval window surgery for the treatment of stapes ankylosis due to otosclerosis was of the indirect type in which attempts were made to mobilize the footplate by forces transmitted through the crura.1Very often, these procedures resulted in crural fracture, and for this reason a direct footplate approach soon was advocated by many otologists. These direct attempts consisted of the use of chisels, pneumatic hammers, and picks of various types. The direct attack on the footplate resulted in higher success rates because the number of crural fractures was reduced, but in many cases the hearing was lost again because of reankylosis of the footplate. It became evident, therefore, that there were two unsolved problems in oval window surgery; accomplishing adequate mobilization while creating or maintaining a "columnella effect," and avoiding reankylosis. Experimental Observations Mucoendosteal Membrane.—In an experiment on cats, Singleton3has shown that footplate fractures