Obliterative otosclerosis.

A total of 2,985 stapedectomies were done during the 25-year period 1959 to 1984 in a busy urban otologic practice. One hundred twenty-three of these cases were found to have obliterative otosclerosis which resulted in a drill-out stapedectomy. Postoperatively, a minimum of 2 years follow-up yielded 98 of the original 123 drill-out cases constituting the study group. Several parameters will be evaluated: 1. Initial hearing gain (measured 3 months after surgery), 2. long-term hearing results (measured 2 years and beyond), 3. additional sensorineural hearing loss, and 4. probability of bilateral obliterative disease.