Paget’s Disease of Bone

Paget's Disease of Bone

WHAT IS PAGET’S DISEASE?

Paget’s disease causes a malfunction in the normal process of bone remodeling. Normally, bone is continually breaking down and rebuilding. This usually slow process of bone destruction and growth is somehow altered and speeded up in Paget’s disease producing a lot of “young bone” which is soft and porous. Soft bone can be weak and easily bend, leading to shortening of the affected part of the body. The bone replacement also takes place very quickly and excess bone may be formed. This can cause the bone to get larger, be painful and break easily.

The bone affected by Paget’s disease also tends to have more blood vessels than normal. This causes an increase in the blood supply to the area, and as a result the area may feel warmer than usual.

The disease can affect any bone but more commonly affects the spine, pelvis, skull, thighbone (femur – pronounced fee-mer) and shinbone (tibia – pronounced ti-bee-ah).

Paget’s disease can lead to other medical conditions including osteoarthritis, kidney stones and heart disease.

Paget’s disease is also called osteitis (pronounced ah-stee-eye-tis) deformans. It is named after Sir James Paget, an English doctor who first described the disease in 1876.

HOW COMMON IS PAGET'S DISEASE?

Paget’s disease is estimated to affect 3% of people over 40, with men being more affected than women. However the exact number is not known because many people who have it do not know it. It occurs all over the world but is more prevalent in some areas, such as in Europe and Australia.

WHAT ARE THE WARNING SIGNS OF PAGET'S DISEASE?

In many cases, Paget’s disease takes a very mild course and a person with it may not have any symptoms. Those who do have symptoms may be affected in various ways.

If you have Paget’s disease your bones may break easily because they are weakened (fracture). Your bones may also bend, and if your leg bones are affected you may notice that your legs bow, or a leg may appear to shrink. If your spine is involved, you may feel pain in your back. If the bones in your spine bend or grow larger than usual this can put pressure on your nerves, and you may feel pain or numbness in other areas of your body also.

If Paget’s disease affects your skull, your head may increase in size from front to back. Hearing loss may result if there is involvement of some of the small bones in the middle ear or pressure is placed on the nerves related to hearing.

In late stages of the disease, your hip joint may become damaged if the bones of your pelvis have been involved.

Usually only one or a few bones are affected. However, the disease can be widespread and affect all bones. Because of the increased number of blood vessels in bones affected by Paget’s disease your heart has to work harder to pump blood to them. If many bones are affected this can cause strain on your heart and lead to other problems.

WHAT CAUSES PAGET'S DISEASE?

Some studies have shown that up to 30% of people with Paget’s disease have other family members with it. The disease is also more prevalent in areas where much of the population is of Anglo-Saxon descent This has led some researchers to believe there may be a genetic factor in the development of Paget’s disease. A slow acting virus may also be involved, though the virus has not yet been identified.

WHAT CAN YOU DO ABOUT PAGET'S DISEASE?

At this time there is no cure for Paget’s disease. Therefore treatment is designed to control the symptoms and change the rate of bone growth. Establishing the correct diagnosis is important because something can be done to manage most forms of arthritis and most therapies work best when started early in the disease.

Your doctor may be able to diagnose Paget’s disease based on your medical history and a physical examination. Your doctor may order certain tests to help confirm the diagnosis and to determine what areas of bone are affected. These tests can include x-rays, bone scans and blood and urine tests.

A diagnosis of Paget’s disease may be made when you see your doctor for another problem. You may have no symptoms at this time, but routine tests may show that you have the disease.

Once diagnosed with Paget’s disease you may be referred to a rheumatologist or other doctor who specializes in bone disorders, or an endocrinologist, who specializes in metabolic and hormonal disorders (which affect the rates of growth in your body).

There is no cure for Paget’s disease but there are treatments that can help you manage the pain and slow the disease. Not everyone with Paget’s disease requires treatment. Treatment is indicated if there is pain, deformity of bones, pressure on nerves or fracture of the affected bone. Your active involvement in developing your treatment plan is essential.

Medicine

A group of prescription drugs known as bisphosphonates have been shown to be helpful in rebuilding bone, and so are used to treat Paget’s disease and other bone diseases. They reverse bone loss by causing the body to produce normal bone. The bisphosphonates that can be prescribed are Didronel, Fosamax, Actonel, Pamidronate and Aclasta.

If you have severe pain from a fracture your doctor may prescribe a medication called calcitonin, which is given by nasal spray. Calcitonin is a hormone that occurs naturally within the body.

For mild to moderate pain from Paget’s disease doctors often recommend acetaminophen (Tylenol®, Panadol®, Exdol®, etc.).

NSAIDs reduce pain when taken at a low dose, and relieve inflammation when taken at a higher dose.

Diet

If you have Paget’s disease you should try to have a proper balance of calcium in your body. Your doctor may advise you to drink about two litres (six to eight glasses) of fluid daily to prevent other complications arising from excess calcium in your body.

However, you should also be sure to have enough calcium in your body. Calcium can be obtained by eating a well-balanced diet that includes foods that are good sources of calcium – for example, milk and milk products, dark-green leafy vegetables (such as mustard greens and kale), and canned fish with soft bones (such as sardines and salmon). Dietary supplements of calcium may be another source.

In general, if you have Paget’s disease you should receive 1000-1500 mg of calcium, adequate sunshine, and at least 1000 units of vitamin D daily. This is especially important if you are being treated with bisphosphonates. If you have a history of kidney stones (calcium deposits in the kidneys) discuss calcium and vitamin D intake with your physician.

Exercise

Exercise may relieve stiffness and help you maintain flexibility. Always consult your doctor before beginning an exercise program. Depending on the severity of your symptoms your doctor may advise against certain exercises. He or she might refer you to a therapist, who can show you the exercises that may be helpful and those that could be harmful.

Surgery

Some people with severe, advanced Paget’s disease may require surgery, though this is rare. Benefits include less pain and better movement and function.

Some kinds of surgery can repair bone deformity or rebuild part of a joint. With other kinds of surgery joints such as hips and knees can be replaced with artificial joints.

Surgery could also be required for badly fractured bones.

log2