Definition 
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, noticeable deformities, and fractures can occur.

Causes 
The cause of Paget’s disease is still not clearly defined. Research findings suggest 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 one member of a family. The hereditary factor may be the reason that family members are susceptible to the suspected virus.

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

Symptoms 
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 increase in 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.

Diagnosis 
Bones affected with Paget’s disease have a characteristic appearance on x-rays. Some-times, 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.

Hearing Loss in Paget’s Disease 

When Paget’s disease affects the skull and the temporal bone (the bone that 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, Paget ’s disease Treatment may slow or stop the progression of the hearing loss. Hearing aids may sometimes help.

Exercise 
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 to discuss the program with your physician, since undue stress on affected bones should be avoided.

Medical Treatment for Paget’s Disease

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 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, oral bisphosphonates should be taken on an empty stomach. The five bisphosphonates currently approved in the U.S. for Paget’s Disease Treatment:
Etidronate disodium (Didronel), which is given in tablet form
Pamidronate disodium (Aredia), which is given intravenously
Alendronate sodium (Fosamax), which is given in tablet form
Tiludronate disodium (Skelid), which is given in tablet form
Risedronate sodium (Actonel TM ), which is also available in tablet form.

Surgical Treatment 
There are generally three major complications of Paget’s disease for which surgery may be recommended. The first is fractures in Pagetic bone. Surgical repair of Pagetic fractures may allow the fracture to 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, surgery 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 you are having surgery, discuss pre-treatment with your physician.

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

For more information, contact:
The Paget Foundation 
120 Wall Street
Suite 1602
New York, NY 10005
(voice) 1-800-23-PAGET or 212-509-5335; (fax) 212-509-8492.