Definition

Paget's disease is a chronic condition that results in enlarged and deformed bones. Although any bone in the body may be affected, the most common sites are the spine, skull, pelvis, thighs, and lower legs. The disease does not usually spread to other normal bones.

Causes

Paget's disease is caused by a malfunction in bone formation. Normally, bones are constantly being broken down by cells called osteoclasts, and rebuilt by cells called osteoblasts. With Paget's disease, bones are broken down abnormally fast, and new bone replacement is loose and bulky, instead of strong and compact. These poorly formed bones may become weak, and may bend over time.

	Normal Bone Structure
	© 2008 Nucleus Medical Art, Inc.

The exact cause of this bone malformation is unknown, but it is associated with heredity. Some experts believe that Paget's may be triggered early in life by a viral infection.

Risk Factors

A risk factor is something that increases your chance of getting a disease or condition. Risk factors for Paget's disease include:

• Family history of Paget's disease, especially in a parent, sibling, or child
• Race: Anglo-Saxon, European
• Age: 40 or older
• In US, residence in northern states

Symptoms

In the early stages, most people have no noticeable symptoms. In later stages, symptoms may include:

• Swelling or deformity of a limb
• Increased head size
• Bowing of a limb
• Curvature of the spine
• Chronic bone pain, especially legs, hips, or spine
• Frequent fractures
• Problems with walking or gait
• Headaches, facial pain, or hearing loss when the skull bones are affected
• Swollen or painful joints due to damaged joint cartilage
• Numbness, tingling, pain, or weakness from pressure on nerves

Depending on the bone site, Paget's disease may result in:

• Arthritis, usually osteoarthritis
• Carpal tunnel syndrome
• High calcium in blood
• Kidney stones
• Hearing problems
• Dental problems
• Rarely:
  • Eye problems
  • Congestive heart failure
  • Bone cancer (sarcoma)

Diagnosis

The doctor will ask about your symptoms and medical history, and perform a physical exam. Tests may include:

• Blood tests—such as those for alkaline phosphatase or calcium
• X-ray —a test that uses radiation to take a picture of the bones
• Bone scan —a series of pictures of bones taken after injection of a small amount of radioactive material

Treatment

Treatment may include:

Medication

Medications may include:

• Pain medicine—such as acetaminophen or nonsteroidal anti-inflammatory drugs
• Bisphosphonates—usually by tablet or by injection
• Calcitonin —administered by injection or nasal spray

Surgery

Surgery may be required if you have one of the following conditions:

• Bone fracture
• Severe degenerative arthritis
• Bone deformity

Self-Care

Recommendations include:

• Calcium , usually about 1,000-1,500 mg per day
• Adequate exposure to sunshine to promote vitamin D production in the skin (but limit time in the sun to prevent sun burning, wrinkling, and aging)
• Intake of adequate vitamin D, usually about 400 mg per day (more may be needed in older people)
• Regular exercise to maintain skeletal health, joint mobility, and normal body weight
• Avoidance of excess mechanical stress on involved bones
• A splint for an area at high risk for fracture

Prevention

There is no known way to prevent the onset of Paget's disease. People with primary family members who have Paget's disease are encouraged to have a routine alkaline phosphatase blood test every two to three years after age 40.

RESOURCES:

Osteoporosis and Related Bone Diseases National Resource Center
http://www.osteo.org

The Paget Foundation for Paget's Disease of Bone and Related Disorders
http://www.paget.org

CANADIAN RESOURCES:

The Arthritis Society
http://www.arthritis.ca

Osteoporosis Canada
http://www.osteoporosis.ca

References:

National Institutes of Health Osteoporosis and Related Bone Diseases, National Resource Center website. Available at: http://www.osteo.org/ . Accessed October 11, 2005.

Schneider D, Hofmann MT, Peterson JA. Diagnosis and treatment of Paget's Disease of bone. Am Fam Physician . 2002 May 15;65(10).

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