Ossicular Chain Dislocation

What is ossicular chain dislocation?

Ossicular chain dislocation is a separation of the middle ear bones. It results in a hearing loss due to sound not being transmitted properly (conductive hearing loss). Ossicular chain dislocation is also called ossicular chain discontinuity.

Ossicular chain dislocation may be caused by:

• A fracture of one of the bones at the side or base of the skull (temporal bone)
• A hole in the eardrum that is caused by trauma (tympanic membrane perforation)
• Chronic otitis media
• Cholesteatoma

Evaluating your child for ossicular chain dislocation

To determine if your child has ossicular chain dislocation, the Children’s Hearing Center team will:

• Evaluate your child’s hearing
• Examine your child’s ear with a microscope
• Request a computed tomography (CT) scan, if needed, to determine the extent of the disease. The CT scan can also provide images to guide surgery.

Ossicular chain dislocation surgery outcomes

The success rate of ossicular chain dislocation repair depends on the stapes.

• If the stapes is intact, the rate of good hearing recovery is about 75 percent. 
• If the stapes is not intact, the rate of good hearing recovery is about 50 percent.

The healing process will also affect your child’s outcome. Scar tissue can pull on the ossicles and/or ossicular prosthesis, moving them from their optimal position. Surgery can often be done again to try to improve hearing.