Frequently Asked Questions

Paget’s disease of bone is a chronic disorder that typically results in enlarged and deformed bones in one or more regions of the skeleton. Excessive bone breakdown and formation can cause the bone to weaken. As a result, bone pain, arthritis, and noticeable deformities, and fractures can occur.

The cause of Paget’s disease is still not clearly defined. Research findings suggests that Paget’s disease may be caused by a “slow virus” infection of bone, a condition that is present for many years before symptoms appear. There is also a hereditary factor since the disease may appear in more than member of a family. This hereditary factor may be the reason that the family members are susceptible to the suspected virus.

Paget’s disease is rarely diagnosed in people under 40. Prevalence in the population ranges from 1.5 percent to 8 percent depending on the person’s age and area of the world where he or she lives. Familial Paget’s disease ranged from 10 percent to 40 percent in different parts of the world. Men and Women are affected equally.

After the age of 40, siblings and children of someone with Paget’s disease may wish to have a standard alkaline phosphatase blood test every two or three years. If the alkaline phosphatase level is above normal, other tests such as bone-specific alkaline phosphatase test, bone scan, or x-ray can be performed.

In mild cases, there may be few symptoms. However, bone pain, the most common symptom can occur in any bone affected by Paget’s disease, and often localizes to areas adjacent to the joints. Headaches and hearing loss may occur when Paget’s disease affects the skull. Pressure on nerves may also occur when the skull or spine is affected. Deformities of bone such as an increased head size, bowing of a limb, or curvature of the spine may occur in advanced cases. These deformities are due to enlargement and/or weakening of the affected bones. Hip pain may occur when the pelvis or thighbone is involved. Bones weakened by Paget’s disease can break more easily than healthy bones. Damage to the cartilage of joints adjacent to the affected bone may lead to arthritis.

No. Many patients who have Paget’s disease do not know they have it since the disease may be so mild that it is not diagnosed. Sometimes the patient’s symptoms are confused with arthritis or other disorders. In other cases, the diagnosis is made only after complications have developed.

Any bone can be affected in Paget’s disease. Paget’s disease occurs most frequently in the spine, skull, pelvis and bones of the lower extremities (thighs and lower legs.) Some patients will have only one affected bone, while others may have two, three, or more affected bones.

Bones affected with Paget’s disease have a characteristic appearance on x-rays. Sometimes, the patient’s doctor is alerted to the possibility of Paget’s disease when a blood test reveals an elevated level of alkaline phosphatase. In such cases, more specific tests may be done. (See question # 4)

Alkaline phosphatase is a chemical (enzyme) that is produced by bone cells and is over-produced by pagetic bone. An elevated alkaline phosphatase level indicated abnormal bone cell activity that can suggest Paget’s disease. In addition to being used as a way of diagnosing Paget’s disease, the alkaline phosphatase level is also used by the physician to monitor a patient’s response to therapy. If a high alkaline phosphatase level is significantly reduced after a period of therapy, then therapy is working for the patient.

Bone scans are useful in Paget’s disease in determining the extent and activity of the condition. Bone scans involve less radiation than x-rays and are also more sensitive than x-rays in detecting areas of bone affected with Paget’s disease. A safe amount of radioactive substance is injected and circulates through the bloodstream. This substance then localizes in areas where there is Paget’s disease. If a bone scan suggests Paget’s disease, the affected bone or bones should be x-rayed to confirm the diagnosis.

The course of Paget’s disease varies greatly and may from completely stable to rapid progression. In general, symptoms progress slowly in affected bones, and there is usually no spread to normal bones. They outlook is generally good, particularly if treatment is given before major changes have occurred. Treatment can control Paget’s disease and lessen symptoms but is not a cure. When untreated, Paget’s disease can cause serious complications, depending on which bones are affected.

Paget’s disease is rarely fatal. Osteogenic sarcoma, a form of bone cancer. is an extremely rare complication that occurs in less than one percent of all Paget’s disease patients. (See question #22)

Paget’s disease can cause arthritis by changing bones around joints: ( 1) Long bones such as in the thigh or leg may become bowed and distort the normal alignment and pressures within the adjacent joints; (2) Pagetic bone may become enlarged, causing the joint surfaces to undergo excessive wear and tear. Osteoarthritis is a very common cause of pain in Paget’s disease. but the disease itself also causes bone pain. In many patients, the pain may be due to a combination of Paget’s disease and osteoarthritis. (See question# 17)

Osteoporosis is a condition of generalized loss of bone mass which can lead to fractures. Although Paget’s disease and osteoporosis can occur in the same patient. they are completely different disorders with different causes. Despite their marked differences, many of the treatments for Paget’s disease can also be used to treat osteoporosis.

In patients with extensive Paget’s disease, the heart has to work harder to pump extra blood to affected bones. This usually does not result in heart failure except in some people who already have heart disease such as arteriosclerosis (hardening) of the arteries of the heart.

There is no direct relationship between Paget’s disease and kidney problems. However, kidney stones are somewhat more common in patients with Paget’s disease.

Pain is the most common symptom that brings a patient with Paget’s disease to a physician. Since most patients with painful symptoms of Paget’s disease do not have obvious deformities, they may not be aware of their correct diagnosis. Pain can take many different forms as shown in the following diagram:

–radicular pain (sciatica)

11171— muscular pain

1-r’!l— osteoarthritic pain

 

 

Thil il/ustr !ion h ;n ad pl rion of a dawing of

Sir J mes P get’! first palienl  with Plget ‘s dise; se.

 

A variety of disturbances of the nervous system can be associated with Paget’s disease of the skull and spinal column. Enlarged pagetic bones can cause pressure on the brain, spinal cord, or nerves. Paget’s disease may cause reduced blood flow to the brain and spinal cord.

When Paget’s disease affects the skull and the temporal bone (the bone which surrounds the inner ear), severe and progressive loss of hearing may occur. This may involve both sides or one side predominantly. If the loss of hearing is progressive and due to Paget’s ·disease, treating the Paget’s disease may slow or stop the progression of the hearing loss. Hearing aids may sometimes help.

Yes. When the skull is involved, the nerves to the eye may be affected and cause some loss of vision; however, this complication is quite rare.

When Paget’s disease affects the facial bones, the teeth may be affected and become loose. Disturbance of the chewing mechanism may occur.

Sarcoma is a malignant bone tumor. Paget’s disease is, on rare occasions, associated with the development of a sarcoma. When there is a sudden onset of severe pain or worsening of previous pain, which is not due to a fi·acture, sarcoma should be considered. In most cases, however, sarcoma is not the cause of increased pain.

No. There is no relationship between the diet and Paget’s disease. In general. people should receive the nutritionally proper amount of calcium (1000-1500 mg daily), adequate sunshine, and at least 400 units of vitamin D daily to maintain a healthy skeleton. A Paget’s disease patient with a history of kidney stones should discuss the use of calcium and his or her vitamin D intake with his or her physician. Adequate calcium and vitamin Dare especially important in patients being treated with bisphosphonatcs. (See question #26)

Exercise is very important in maintaining skeletal health and is recommended for patients with Paget’s disease. Exercise is also helpful in avoiding weight gain and in maintaining the mobility of the joints. Before beginning any exercise program, it is wise for a patient to discuss the program with his or her physician since undue stress on affected bones should be avoided.

Endocrinologists (physicians who specialize in hormonal and metabolism disorders) and rheumatologists (physicians who specialize in joint and muscle disorders) are internists who are generally knowledgeable about treating Paget’s disease. Also, orthopedic surgeons, neurologists, and otolaryngologists (physicians who specialize in ear. nose, and throat disorders) may be called upon to evaluate specialized symptoms in Paget’s disease.

The goal of treatment is to normalize Paget’s disease activity for a prolonged period of time. In general, the therapies of choice are the three more potent bisphosphonates: Actonel™, Fosamax@ and Aredia®. Didronel®, Skelid® or Miacalcin® may be appropriate therapies for selected patients. Following is information about all therapies approved by the U.S. Food and Drug Administration (FDA) for the treatment of Paget’s disease:

Calcitonin. Miacalcin® is a brand of synthetic salmon calcitonin that is taken by injection. The dose may vary from 50 units to 100 units, taken daily or three times a week for 6 to 18 months. Repeat courses can be given after brief rest periods.

Bisphosphonates. Five bisphosphonates are currently available. Four are in tablet form and one is in intravenous form. As a rule, bisphosphonate tablets should be taken on an empty stomach. Specific instructions for taking each drug are included in the chart that follows. Also, an adequate dietary calcium intake (1000-1500 mg daily) and vitamin D intake (400 units) are recommended during bisphosphonate use, except if there is a history of kidney stones containing calcium. The recommended dosages that follow are those approved by the FDA. However, experienced physicians may sometimes
prescribe different doses. None of these drugs should be used by people with severe kidney disease.

Some therapies approved for other conditions can sometimes be used for Paget’s disease. Miacalcin® nasal spray is currently approved only for treatment of postmenopausal osteoporosis.

There are generally three m jor complications of Paget’s disease for which surgery may be recommended. The first is fractures in pagetic bone. Surgical repair of fractures in bones with Paget’s disease may help the fractures heal in better position. The second complication occurs when the patient develops severe degenerative arthritis. If medication and physical therapy are no longer helpful, and if disability is severe, joint replacement of the hips and knees may be considered as an option. The third situation involves bone deformity, especially of the tibia. The surgical cutting and realignment of a pagetic bone (osteotomy) may help painful weight-bearing joints, especially the knees. Medical therapy prior to surgery helps to decrease bleeding and other complications during surgery. If a patient is having surgery, he or she should discuss pre-treatment with the physician.

Rarely. Enlargement of the skull may cause the back of the skull to deform and injure the nervous system. This can be helped by neurosurgery. Similarly, bone in the spine may overgrow and compress the spinal cord and spinal nerves. Often, however, most moderately severe neurologic symptoms can be treated with medication and do not require surgery.