Otosclerosis is a disorder of the third hearing bone (stapes) that causes a conductive hearing loss. Please see our section on types of hearing loss and how the ear works to better understand how otosclerosis affects your hearing.
Who gets otosclerosis and why does it occur?
Otosclerosis develops most frequently in people between the ages of 10 and 30. In most cases, both ears are affected; however, about 10–15% of patients diagnosed with otosclerosis have loss of hearing in only one ear. The disorder affects women more frequently than men by a ratio of 2:1. Pregnancy was once thought to be a risk factor for the development and / or worsening of otosclerosis however recent studies have disputed this.
Some forms of the disease may progress to nerve deafness called cochlear otosclerosis. This is diagnosed by hearing test and high resolution CT scan of the ear. This is why all patients who are seen for otosclerosis at the Capital Region Ear Institute routinely have a CT scan done prior to any surgical intervention. The treatment of the disorder is controversial. Traditionally, patients have been given fluoride supplementation. Flouride may have side effects including upset stomach, allergic reactions, increased joint pain, and aggravation of arthritis. There have been no studies to show that this therapy is of any value for therapy and so Fluoride is not routinely prescribed for cochlear otosclerosis at the Capital Region Ear Institute.
There are three options for patients with otosclerosis.
The first is simple observation. This is reserved for individuals with very mild disease. The disease usually progresses to further hearing loss over time and eventually requires intervention.
The second is amplification (hearing aids). Hearing aids are very effective in overcoming the hearing loss associated with otosclerosis. There is essentially no risk to wearing hearing aids. The downside of hearing aids is the cost, potential discomfort, requirement that the person wear the aid, and variable sound quality.
The third option is a surgical procedure called a stapedectomy. The surgery along with risks and benefits will be explained bellow. In general, the surgery has a risk of further hearing loss in about 1 percent of patients and may be permanent and un-repairable.
Surgery For Otosclerosis
The surgery for otosclerosis is called a “middle ear exploration and stapedectomy.” Dr. Foyt has personally performed hundreds of stapes operations. The particular technique that he uses is the “minimal fenestra stapedectomy.” This procedure is believed to be safer and less traumatic than traditional techniques that require complete removal of the stapes footplate. The procedure is performed with a state of the art microcsopic carbon dioxide laser which allows very precise manipulation of the middle ear structures.
Stapedectomy is performed through the ear canal under general anesthesia as an outpatient procedure. An operating microscope is used in order to visualize the delicate structures of the middle ear. Prior to surgery a blood sample is taken which will later be used to seal the inner ear at the termination of the procedure. Tissue may also be removed from the ear cartilage (perichondrium) to help seal the inner ear.
The procedure is essentially painless as it is done with the person asleep under general anesthesia.
An incision is made in the ear canal skin. The skin of the ear canal is elevated along with the eardrum to reveal the delicate structures of the middle ear.
A microscopic drill is then used to remove some excess bone of the ear canal if needed. The laser is used to then remove the third hearing bone (stapes). The mobility of the other hearing bones is first check. In a small number of patients some or all of the other hearing bones may be involved requiring alteration of the procedure.
Once the third hearing bone is removed by the laser a hole is created exactly 0.6 – 0.7 millimeters in diameter. The stapes prosthesis has a diameter of 0.5 millimeters and is 4.0 to 4.0 mm in length depending on size chosen by the surgeon. A small amount of fat is harvested from the ear lobe and placed around the prosthesis. A small amount of blood is also taken at the time of surgery and placed into the middle ear before the drum is closed.
The tolerances for this procedure are within tenths of a millimeter for optimum results.
Most surgeons require an experience of over a hundred procedures to achieve proficiency and hundreds of cases to become a master. Additionally, continuous practice with frequent surgery is required to maintain expertise.
This is a video of the Stapedectomy Surgery. The operation is done through the ear canal, under general anesthesia, and takes approximately 30 minutes. Patients go home the same day and hearing is usually restored in four to six weeks. During the video you will see how the eardrum is opened and the tiny Stapes Bone is removed with a very precise laser. The Stapes Bone is then replaced by a prosthesis that transmits sound from the eardrum to the delicate nerve endings of the inner ear.
What to Expect After Surgery
Patients almost always are able to go home on the same day of surgery. Patients are told that they will have almost no hearing in the operated ear due to the blood and fat patches that are place into the middle ear. Dizziness may be experienced by some people and generally improves with head elevation. Some individuals may experience a metallic taste on a corner of the tongue. This is related to the stretching of a nerve called the chorda tympani which travels in the middle ear but innervates a portion of the tongue. This usually resolves within a few weeks.
Patients are instructed to return to the Ear Institute one week after surgery, and then two weeks later. Hearing improvement occurs three to six weeks after surgery.
The prosthesis is designed for life-long use. In a small number of patients the prosthesis can become lose or the hearing bones may degenerate requiring a revision surgery to restore hearing.