What Is Ossicular Fixation?
During the natural process of hearing sound waves travel through the air, down the ear canal funnel, and vibrate the eardrum. This sets the ossicles into motion. The ossicles are the three smallest bones in the human body. They are called the malleus, the incus, and the stapes. Their movements transmit sound into the inner ear for processing. Ossicular fixation results when the malleus or incus are unable to move properly, or are fixed.
What Are the Symptoms of Ossicular Fixation?
Conductive hearing loss results when the ossicular chain is fixed. Conductive hearing loss is the type of hearing loss that occurs when sound waves are not smoothly transmitted into the inner ear. It is contrasted with sensorineural hearing loss which occurs when the processing of sound is impaired by loss of cochlea, auditory nerve, or central auditory function.
Some cases of ossicular fixation cause mixed hearing loss. This is a combination of both conductive and sensorineural hearing loss.
How Did I Get Ossicular Fixation in the First Place?
Ossicular fixation may occur before you are born. During development, the ossicular chain develops during the fourth week. Problems with this develop cause incomplete formation of the malleus and incus or fusion of the ossicules to wall of the middle ear.
Ossicular fixation can also be the result of chronic ear infections. The cycle of continued inflammation causes the ligaments of the ossicles to harden into solid bone. The ossicles are then fused to the walls of the middle ear.
How Will My Doctor Test for Ossicular Fixation?
Ossicular fixation is a rare cause of conductive and mixed hearing loss. Discussion of your symptoms and hearing testing may lead to suspicion, but actual diagnosis is usually only possible during surgery. During a procedure called middle ear exploration, your doctor will elevate the eardrum and assess the mobility of the ossicles.
Is Ossicular Fixation Treatable?
The hearing loss of ossicular fixation is typically serviceable with a hearing aid. A conventional hearing aid is one option. Bone conducting hearing aids are also options. Repair of ossicular fixation is also possible. If ossicular fixation is diagnosed during middle ear exploration, ossiculoplasty can be performed. This means removing the nonfunctioning ossicles and replacing them with an ossicular prosthesis. This is a tiny medical device placed in the middle ear that connects the eardrum to the inner ear.