Paget's Disease of Bone: Symptoms, Complications and Treatment

Bone is constantly being broken down and rebuilt. In Paget's disease of bone, a chronic disorder, that process goes wrong: bone breaks down and regrows too much. Because it regrows too fast, the new bone is larger and softer than normal, and it can be misshapen and break easily. Paget's disease usually affects just one or a few bones.

Causes and risk

Researchers do not know for certain what causes Paget's disease. Environmental factors may play a part. It sometimes runs in families, and several genes have been linked to it. It is more common in older people and in people of northern European heritage, and having a close relative with Paget's makes it much more likely.

Symptoms

Many people with Paget's disease never know they have it, because it often causes no symptoms. When it does, they resemble those of arthritis and other disorders:

• pain, from the disease itself or from arthritis it causes
• headaches and hearing loss, when it affects the skull
• pressure on nerves, when it affects the skull or spine
• a larger head, a bowed limb or a curved spine, in advanced cases
• hip pain, when it affects the pelvis or thighbone
• damage to joint cartilage, which can lead to arthritis

The disease usually worsens slowly and does not spread to normal bones.

Complications

• Arthritis: misshapen bones put extra pressure and wear on joints.
• Heart failure: in severe disease the heart must work harder to supply the affected bones, and the risk is higher with hardening of the arteries.
• Kidney stones: heavy bone breakdown can leave extra calcium in the body.
• Nervous system problems: bone can press on the brain, spinal cord or nerves, and blood flow to the brain and spinal cord may be reduced.
• Osteosarcoma, a cancer of the bone.
• Loose teeth, when the facial bones are affected.
• Vision loss, rarely, when disease in the skull affects the nerves.

Diagnosis

A provider may use a medical history, a physical exam, x-rays of the affected bones, an alkaline phosphatase blood test and a bone scan. X-rays are almost always how the diagnosis is made. Paget's disease is sometimes found by chance when one of these tests is done for another reason.

Treatment

Finding and treating the disease early helps prevent complications.

Medicines. Several are available. The most common are bisphosphonates, which ease bone pain and stop or slow the disease.

Surgery is sometimes needed for complications:

• to help a broken bone heal in a better position
• to replace a joint such as the knee or hip when arthritis is severe
• to realign a deformed bone and ease pain in weight-bearing joints, especially the knees
• to relieve pressure on a nerve when an enlarged skull or spinal injury affects the nervous system

Diet and exercise do not treat Paget's disease, but they help keep the skeleton healthy. People without kidney stones should get enough calcium and vitamin D from food and supplements. Exercise also helps prevent weight gain and keeps joints mobile, but check with a provider before starting a new program to make sure it will not put too much stress on the affected bones.

Sources

• MedlinePlus (National Library of Medicine), "Paget's Disease of Bone," from the National Institute of Arthritis and Musculoskeletal and Skin Diseases. https://medlineplus.gov/pagetsdiseaseofbone.html
• The source's "effects the nervous system" is corrected to "affects."