noun. a development of spongy bone which grows in the middle ear and immobilizes the stapes at the place of connection to the oval window facing the inner ear. Otosclerosis is characterized by persistent deafness as the ossicles are unsuccessful at conveying vibrations from the tympanic membrane to the inner ear. It is thought to be genetic.
OTOSCLEROSIS: "The otosclerosis will be very difficult and risky to remove without damaging other structures of the ear."