Paget disease of the bone

Osteitis deformans

The cause of Paget disease is unknown. It may be due to genetic factors or a viral infection early in life.

The disease occurs worldwide, but is more common in Europe, Australia, and New Zealand. The disease has become much rarer over the last 50 years.

In people with Paget disease, there is an abnormal breakdown of bone tissue in specific areas. This is followed by abnormal bone formation. The new area of bone is larger, but weaker. The new bone is also filled with new blood vessels.

The affected bone may only be in 1 or 2 areas of the skeleton, or throughout the body. It more often involves bones of the arms, collarbones, leg, pelvis, spine, and skull.

Most people with the condition have no symptoms. Paget disease is often diagnosed when an x-ray is done for another reason. It may also be discovered when trying to find the cause of high blood calcium levels.

If they do occur, symptoms may include:

• Bone pain, joint pain or stiffness, and neck pain (the pain may be severe and present most of the time)
• Bowing of the legs and other visible deformities
• Enlarged head and skull deformities
• Fracture
• Headache
• Hearing loss
• Reduced height
• Warm skin over the affected bone

Tests that may indicate Paget disease include:

• Bone scan
• Bone x-ray
• Elevated markers of bone breakdown (for example, N-telopeptide)

This disease may also affect the results of the following tests:

• Alkaline phosphatase (ALP), bone specific isoenzyme
• Serum calcium

Not all people with Paget disease need to be treated. People who may not need treatment include those who:

• Only have mildly abnormal blood tests
• Have no symptoms and no evidence of active disease

Paget disease is commonly treated when:

• Certain bones, such as weight-bearing bones, are involved.
• Bony changes are getting worse quickly (treatment can reduce the risk of fractures).
• Bony deformities are present.
• A person has pain or other symptoms.
• The skull is affected. (This is to prevent hearing loss.)
• The calcium levels are elevated and causing symptoms.

Drug therapy helps prevent further bone breakdown and formation. Currently, there are several classes of drugs used to treat Paget disease. These include:

• Bisphosphonates: These drugs are the first treatment, and they help decrease bone remodeling. Medicines are commonly taken by mouth, but can also be given through a vein (intravenously).
• Calcitonin: This hormone is involved in bone metabolism. It may be given as a nasal spray (Miacalcin), or as an injection under the skin (Calcimar or Mithracin)

Acetaminophen (Tylenol) or nonsteroidal anti-inflammatory drugs (NSAIDs) may also be given for pain. In severe cases, orthopedic surgery may be needed to correct a deformity.

People with this condition may benefit from taking part in support groups for people with similar experiences.

Most of the time, the condition can be controlled with medicines. A small number of people may develop a cancer of the bone called osteosarcoma. Some people will need joint replacement surgery.

Complications may include:

• Bone fractures
• Deafness
• Deformities
• Heart failure
• Hypercalcemia
• Paraplegia
• Spinal stenosis

Call your health care provider if you develop symptoms of Paget disease.