October 12, 2016

Otosclerosis

Eargraphic

Otosclerosis is a condition affecting the temporal bone, the bone containing the structures of the ear.  Normal bone becomes replaced with disorganized “spongiotic” and “sclerotic” bone.  This usually affects the part of the temporal bone around the oval window, which is the interface between the stapes, or third bone of hearing and the inner ear.  This causes calcification and stiffening of the ligament that supports the stapes, reducing its ability to vibrate and transmit sound effectively.  This causes a conductive hearing loss, which implies a mechanical problem regulating sound from the environment to the inner ear, where it is detected.  In some cases otosclerosis may progress to involve the inner ear itself, causing a sensorineural hearing loss.  Otosclerosis affects up to 10% of the white population.  It is much less common in other ethnic groups, and impacts women more commonly than men.  It occurs in both ears to some degree in the majority of patients, though it may progress at varying rates.  Otosclerosis tends to run in families.

Treatment Options for Otosclerosis include Hearing Aids and Surgery.

What happens during surgery?

Surgery is usually performed under general anesthesia.  Depending on the size and shape of the ear canal, surgery can often be performed with a single small incision hidden inside the ear canal. Occasionally, a small extension of the incision out of the ear canal and into the crease in front of your ear may be needed. The eardrum is lifted up to access the middle ear. A small portion of the innermost ear canal bone is removed to access the stapes and oval window. The stapes is separated from its attachment to the incus. A laser is then used to divide a tendon attached to the stapes, as well as the portions of the stapes connected to the footplate (part that is within the oval window). The stapes is removed with the exception of the footplate, which is left in place. A laser and very tiny drill is used to create a precise hole in the footplate into the inner ear. A prosthesis called a stapes piston is then positioned between the incus (hearing bone that was connected to the stapes) and the hole (stapedotomy), thus restoring the connection between the mobile hearing bones and the inner ear. The eardrum is then repositioned and secured in place with some tiny pieces of absorbable packing sponge.