Paget's disease of bone

Overview

Paget's (PAJ-its) disease of bone interferes with your body's normal recycling process, in which new bone tissue gradually replaces old bone tissue. Over time, bones can become fragile and misshapen. The pelvis, skull, spine and legs are most commonly affected.

The risk of Paget's disease of bone increases with age and if family members have the disorder. However, for reasons unknown to doctors, the disease has become less common over the past several years and is less severe when it does develop. Complications can include broken bones, hearing loss and pinched nerves in your spine.

Bisphosphonates — the medications used to strengthen bones weakened by osteoporosis — are the mainstay of treatment. Surgery may be necessary if complications occur.

Symptoms

Most people who have Paget's disease of bone have no symptoms. When symptoms occur, the most common complaint is bone pain.

Because this disease causes your body to generate new bone faster than normal, the rapid remodeling produces bone that's less organized and weaker than normal bone, which can lead to bone pain, deformities and fractures.

The disease might affect only one or two areas of your body or might be widespread. Your signs and symptoms, if any, will depend on the affected part of your body.

• Pelvis. Paget's disease of bone in the pelvis can cause hip pain.
• Skull. An overgrowth of bone in the skull can cause hearing loss or headaches.
• Spine. If your spine is affected, nerve roots can become compressed. This can cause pain, tingling and numbness in an arm or leg.
• Leg. As the bones weaken, they may bend — causing you to become bowlegged. Enlarged and misshapen bones in your legs can put extra stress on nearby joints, which may cause osteoarthritis in your knee or hip.

When to see a doctor

Talk to your doctor if you have:

• Pain in your bones and joints
• Tingling and weakness in an extremity
• Bone deformities
• Unexplained hearing loss, especially if it's only on one side

Causes

The cause of Paget's disease of bone is unknown. Scientists suspect a combination of environmental and genetic factors contribute to the disease. Several genes appear to be linked to getting the disease.

Some scientists believe Paget's disease of bone is related to a viral infection in your bone cells, but this theory is controversial.

Risk factors

Factors that can increase your risk of Paget's disease of bone include:

• Age. People older than 50 are most likely to develop the disease.
• Sex. Men are more commonly affected than are women.
• National origin. Paget's disease of bone is more common in England, Scotland, central Europe and Greece — as well as countries settled by European immigrants. It's uncommon in Scandinavia and Asia.
• Family history. If you have a relative who has Paget's disease of bone, you're more likely to develop the condition.

Complications

In most cases, Paget's disease of bone progresses slowly. The disease can be managed effectively in nearly all people. Possible complications include:

• Fractures and deformities. Affected bones break more easily, and extra blood vessels in these deformed bones cause them to bleed more during repair surgeries. Leg bones can bow, which can affect your ability to walk.
• Osteoarthritis. Misshapen bones can increase the amount of stress on nearby joints, which can cause osteoarthritis.
• Neurological problems. When Paget's disease of bone occurs in an area where nerves pass through the bone, such as the spine and skull, the overgrowth of bone can compress and damage the nerve, causing pain, weakness or tingling in an arm or leg or hearing loss.
• Heart failure. In severe cases, your heart may have to work harder to pump blood to the affected areas of your body. Sometimes, this increased workload can lead to heart failure.
• Bone cancer. Bone cancer occurs in up to 1% of people with Paget's disease of bone.

Diagnosis

During the physical exam, your doctor will examine areas of your body that are causing you pain. He or she may also order X-rays and blood tests that can help confirm the diagnosis of Paget's disease of bone.

Imaging tests

Bone changes can be revealed by:

• X-rays. The first indication of Paget's disease of bone is often abnormalities found on X-rays done for other reasons. X-ray images of your bones can show areas of bone breakdown, enlargement of the bone and deformities that are characteristic of the disease, such as bowing of your long bones.
• Bone scan. In a bone scan, radioactive material is injected into your body. This material travels to the spots on your bones most affected, and they light up on the scan images.

Lab tests

People who have Paget's disease of bone usually have elevated levels of alkaline phosphatase in their blood, which can be revealed by a blood test.

Treatment

If you don't have symptoms, you might not need treatment. However, if the disease is active — indicated by an elevated alkaline phosphatase level — and is affecting high-risk sites in your body, such as your skull or spine, your doctor might recommend treatment to prevent complications, even if you don't have symptoms.

Medications

Osteoporosis drugs (bisphosphonates) are the most common treatment for Paget's disease of bone. Bisphosphonates are typically given by injection into a vein, but they can also be taken by mouth. When taken orally, bisphosphonates are generally well tolerated but can irritate the stomach.

Bisphosphonates that are given intravenously include:

• Zoledronic acid (Zometa, Reclast)
• Pamidronate (Aredia)
• Ibandronate (Boniva)

Oral bisphosphonates include:

• Alendronate (Fosamax, Binosto)
• Risedronate (Actonel, Atelvia)

Rarely, bisphosphonate therapy has been linked to severe muscle, joint or bone pain, which might not resolve when the medication is discontinued. Bisphosphonates can also increase the risk of a rare condition in which a section of jawbone dies and deteriorates, usually associated with active dental disease or oral surgery.

If you can't tolerate bisphosphonates, your doctor might prescribe calcitonin (Miacalcin), a naturally occurring hormone involved in calcium regulation and bone metabolism. Calcitonin is a drug that you administer to yourself by injection or nasal spray. Side effects may include nausea, facial flushing and irritation at the injection site.

Surgery

In rare cases, surgery might be required to:

• Help fractures heal
• Replace joints damaged by severe arthritis
• Realign deformed bones
• Reduce pressure on nerves

Paget's disease of bone often causes the body to produce too many blood vessels in the affected bones, increasing the risk of serious blood loss during an operation.

If you're scheduled for surgery that involves bones affected by Paget's disease of bone, your doctor might prescribe medications to reduce the activity of the disease, which may help reduce blood loss during surgery.

Self care

To reduce your risk of complications associated with Paget's disease of bone, try these tips:

• Prevent falls. Paget's disease of bone puts you at high risk of bone fractures. Ask your doctor for advice on preventing falls. He or she may recommend that you use a cane or a walker.
• Fall-proof your home. Remove slippery floor coverings, use nonskid mats in your bathtub or shower, tuck away cords, and install handrails on stairways and grab bars in your bathroom.
• Eat well. Be sure your diet includes adequate levels of calcium and vitamin D, which helps bones absorb calcium. This is especially important if you're taking a bisphosphonate. Review your diet with your doctor and ask if you should take vitamin and calcium supplements.
• Exercise regularly. Regular exercise is essential for maintaining joint mobility and bone strength. Talk to your doctor before beginning an exercise program to determine the right type, duration and intensity of exercise for you. Some activities may place too much stress on your affected bones.

Preparing for your appointment

Most people with Paget's disease of bone don't have any symptoms and are diagnosed when an X-ray or blood test taken for another reason reveals signs of Paget's disease of bone. In some cases, you may be referred to a doctor who specializes in metabolic and hormonal disorders (endocrinologist) or in joint and muscle disorders (rheumatologist).

Here's some information to help you get ready for your appointment.

What you can do

When you make the appointment, ask if there's anything you need to do in advance, such as fasting before having a specific test. Make a list of:

• Your symptoms, including any that seem unrelated to the reason for your appointment
• Key personal information, including major stresses, recent life changes and family medical history
• All medications, vitamins or other supplements you take, including the doses
• Questions to ask your doctor

Take a family member or friend along, if possible, to help you remember the information you're given.

For Paget's disease of bone, some basic questions to ask your doctor include:

• What's likely causing my symptoms?
• What are other possible causes for my symptoms?
• What tests do I need?
• Is my condition likely temporary or chronic?
• What's the best course of action?
• What are the alternatives to the primary approach you're suggesting?
• How can I best manage this condition with my other health conditions?
• Are there restrictions I need to follow?
• Should I see a specialist?
• Are there brochures or other printed material I can have? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

Your doctor is likely to ask you some of the following questions:

• Have you had numbness or tingling?
• How about muscle weakness?
• Any new headaches?
• Has your hearing recently worsened?