PAGET'S DISEASE OF BONE
Paget's disease of bone is an unusual, chronic bone condition that occurs in only about 1% of people in the United States and slightly more often in men than in women (3 to 2). Individuals with Paget's disease experience rapid bone repair which causes a variety of symptoms from softer bones to enlarged bone growth, typically in the pelvis, back (spine), hips, thighs, head (skull) and arms. Medical therapies have proven effective in reducing the pain, fractures and arthritis that may be caused by this condition.
Normally, as people age, their bones rebuild at a slower rate. For those with Paget's disease, however, this process of rebuilding bones takes place at a faster rate. As a result, the rebuilt bone has an abnormal structure. The involved bone can be soft, leading to weakness and bending of the pelvis, back (spine), hips, thighs, head and arms. Or the regrowth can cause the bone to enlarge, making it more susceptible to arthritis, hearing loss, fractures and discomfort.
Given this takes place in those over the age of 40, the symptoms are often mistaken for changes associated with aging.
Causes
The cause of Paget's disease is unknown. It does appear to be, at least partially, due to heredity, perhaps when activated by exposure to a virus.
Diagnosis
Paget's disease is rarely discovered in individuals before they reach the age of 40, and the numbers of people identified seem to increase in each progressive age group.
Typically, it is the appearance of the bones on an X-ray that signals the physician to make the diagnosis. Blood tests taken will most often indicate an increase in serum alkaline phosphatase (SAP) which is reflective of the rapid new bone turnover. Urine test results also will indicate the speed at which this rebuilding is taking place.
Physicians usually obtain a non-invasive 'bone scan' to determine the extent of bone involvement. Only if cancer is suspected will it be necessary to biopsy the bone to examine it under a microscope.
Treatment
Treatment approaches can focus on providing physical assistance including the addition of wedges in the shoe, canes as walking aids and the administration of physical therapy.
Medications that help reduce the pain associated with Paget's disease include acetaminophen (e.g., Tylenol), anti-inflammatory drugs such as ibuprofen and naproxen, and a group of medications called 'bisphosphonates.' Bisphosphonates help the body regulate the bone building process so as to produce more normal bone growth. Your physician may prescribe:
- Alendronate (Fosamax) or etidronate (Didronel) to be taken by mouth every day for 6 months.
- Tiludronate (Skelid) to be taken by mouth every day for 3 months.
- Risedronate (Actonel) to be taken by mouth every day for 2 months.
All oral medications should be taken with a large glass of water (6-8 oz) upon arising in the morning. Patients should remain upright for the next 30 minutes and not eat until that time has passed. Any of these treatments can be repeated if necessary. Side effects of these medicines may involve heartburn and sometimes increasing bone pain for a short period of time.
Injectable medications that can be given for Paget's disease of bone include:
- Pamidronate (Aredia) injected in the vein at intervals separated by a month or several months. Unusually, there can be inflammation of the eye or loss of bone around the teeth (osteonecrosis).
- Calcitonin, which is a hormone, is injected under the skin.
Medical treatment is not expected to correct some of the changes of the Paget's disease that have already occurred, such as hearing loss, deformity or osteoarthritis.
Informations obtained from National Institute of Health.