A Stapedectomy (Hearing Surgery) is ear surgery that can be done to treat hearing loss caused by a problem called otosclerosis. Otosclerosis causes a buildup of bone around the stapes (stirrup bone). The buildup of bone keeps the stapes from moving normally, resulting in a hearing loss called conductive hearing loss. The surgery is done to replace the stapes with an artificial part. After the surgery, sound can again be transmitted from the eardrum to the inner ear.
This operation is used when the primary cause of a hearing loss is decreased movement of the stapes (otosclerosis). If both ears have this problem, the ear with worse hearing is treated first.
Types of Hearing Impairment
The external ear and the middle ear conduct sound; the inner ear receives it. If there is some difficulty in the external or middle ear, a conductive hearing impairment occurs. If the trouble lies in the inner ear, a sensorineural or nerve hearing impairment is the result. When there is difficulty in both the middle and the inner ear a mixed or combined impairment exists. Mixed impairments are common in otosclerosis.
Hearing Impairment from Otosclerosis
If we had been able to examine your middle ear under the microscope before a hearing impairment developed, we could have seen minute areas of both softening and hardening of the bone. This process may spread to the stapes, the inner ear, or to both sides.
When otosclerosis spreads to the inner ear, a sensorineural hearing impairment may result due to interference with the nerve function. This nerve impairment is called cochlear otosclerosis and one it develops it may be permanent. On occasion, the otosclerosis may spread to the balance canals and may cause episodes of unsteadiness.
Usually, otosclerosis spreads to the stapes or stirrup none, the final link in the middle ear transformer chain. The stapes rests in the small groove, the oval window, in intimate contact with the inner ear fluids. Anything that interferes with its motion results in a conductive hearing impairment. This type of impairment is called stapedial otosclerosis and is usually correctable by surgery.
The amount of hearing loss due to the involvement of the stapes and the degree of nerve impairment present can be determined only by audiometric examination (hearing tests).