Otosclerosis is a disorder that can cause progressive hearing loss. It is caused by an abnormality in the metabolism of calcium in the bony junction between the middle ear bones and the inner ear bones.
Three tiny bones in the ear vibrate to keep sound waves moving into the inner ear. The stapes is the third bone in the chain, and the one directly connected to the inner ear. If the stapes becomes fixed and stops vibrating, it can lead to hearing loss in one or both ears.
Hearing Loss from Otosclerosis
Hearing loss from otosclerosis is progressive, and usually begins in early adulthood. But children can also be affected, and in rare situations, otosclerosis can occur at or very near birth.
Pregnancy can often cause the disease to accelerate, and many women do not notice their hearing loss until during or shortly after pregnancy.
Otosclerosis causes conductive (or occasional mixed) hearing loss — the inner ear hears normally, but sound is not properly conducted through the middle ear. As the stapes bone becomes stiffer, the hearing loss becomes more pronounced.
Treating Hearing Loss from Otosclerosis
Otosclerosis cannot be cured, but the hearing loss it causes can be overcome. The three major treatments include:
- Hearing aids can almost always overcome the conductive hearing loss, although loss continues to progress over time.
- Bone-anchored auditory implants can be extremely successful in correcting the hearing loss without risking damage to the middle or inner ear. This involves the surgical placement of a titanium post in the skull behind the ear and using a vibrating hearing aid attachment. Sound can stimulate the inner ear directly and bypass the nonfunctional hearing bones.
- Stapedectomy is a microsurgery to remove the fixed bone and replace it with an artificial one. The artificial prosthesis is usually made of titanium.
Research shows that stapedectomy is successful in restoring normal or near normal hearing in 90 percent to 95 percent of patients. The surgery is performed as an outpatient and takes approximately 45 to 60 minutes.
Candidates for stapedectomy include those who have:
- Conductive (rather than neurological) hearing loss
- Good word-understanding ability
- No adverse ear canal, eardrum or other middle ear conditions
People with other problems in the ear canal, ear drum, or middle ear can often have stapedectomy surgery, but these conditions usually need to be corrected first.
Many people have otosclerosis in both ears. Stapedectomy surgery can be done in both ears, but not at the same time. Typically the second ear is done eight to 12 months after the first one.