Paget's Disease

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What is Paget's Disease?

    Paget's Disease, also known as osteitis deformans, is a thickening and weakening of the bone. It usually is of the pelvis, collarbone, spine, skull, lower leg, thigh bones, and the humerus, or upper arm bone (Komaroff, 1999).  This is a metabolic bone disease which involves the destruction and regrowth of new bone that results in deformity.  The occurrence of Paget's disease is seen greatest in the pelvis in 65% of all cases, followed by the spine in a rate of about 42%, and the femur in 37% (Miller, 1999).  This disease is uncommon in a patients under the age of 55 years, but relatively common later in life, occurring in 3-4% of people over the age of 55 years and a 10% occurrence rate in the population over the age of 80 (Frassica, 1998).  Paget's disease also affects men twice as often as it does women.

    There are three basic phases of Paget's disease.  The first is the hypervascular or osteolytic phase.  It is the initial phase involving bone resorption by the osteoclasts.  This phase causes increased blood flow to the involved bones.  Degenerative arthritis is associated with the hypervascular phase in the ends of the bones.  The second phase is the intermediate phase.  During this phase bone structure changes and bone deformities are manifested.  The final stage of the disease is the quiescent stage.  There no longer any evidence of increased turnover of bone, and enlargement and widening in this stage (Frassia, 1998).

    The cause of Paget's disease is not known, although it seems to run in families (Komaroff, 1999). It is suspected that Paget's disease is caused by a virus, but scientists are still not certain.

    Symptoms associated with Paget's disease are bone pain that may be severe and persistent with accompanying joint pain or stiffness.  Also among the most common symptoms are headache, spinal curvature, bowing of the legs, a barrel shaped chest, neck pain, reduction in height, blindness, and hearing loss.  It is also possible to have Paget's disease and have no symptoms at all.  Signs that may be discovered by the physician are increased bone density, bowing, and elevated calcium levels.

    The diagnosis of Paget's disease is made through a series of several tests ordered by a physician.  Bone x-rays are performed to show if there is any increase in bone density.  The radiograph will appear to have whiter areas where the disease is present, which indicates increased bone density in that particular region.  Also a nuclear medicine bone scan may be performed.  Below are examples of what the bone scan films would look like.  The darker areas on the scan indicate an area affected by Paget's disease.

           Humerus                      Femur                  Pelvis & Femur

    Also some laboratory tests can help diagnose Paget's disease as well.  An elevated serum alkaline phosphate, which reflects an increase in bone formation, is a result of Paget's disease.  The uric acid level may also be increased.  A CBC that indicates anemia is also an indication of Paget's disease.

    Paget's disease is not infectious (Weisse, 1999).  Localized Paget's disease, which means it is confined to a certain area of the skeleton, requires relatively no treatment.  If needed nonsteriodal medications may be given for pain.  Orthopedic surgery may be required to correct any specific deformities.  Drug therapy may also be used.  It is aimed at suppressing bone cellular activity and mineral changes that influence the disease process.  Calcitonin is given to retard bone resorption and affect bone lesions.

    This disease has the capability of malignant changes of bone occurring in about 5% of people affected.  The disease may remain localized and result in little deformity, or become widespread with multiple skeletal deformities.  It is not yet known whether long-term treatment will decrease the bone enlargement or deformity or reduce the risk of fracture (Frassica, 1998).
 
 

    Komaroff, A. L.  (Ed.).  (1999).  Harvard Medical School Family Health Guide.  New York, NY:  Simon and Schuster.

    Weisse, A. (1999).  The Hypochondriac's Guide to Life and Death  Journals of the AMA  [On-line],  Available:  http://jama.ama-assn.org  (January 27, 2000).

    Frassica, F. J. (1998).  Survival and management considerations in postirridiation osteosarcoma and Paget's osteosarcoma  Wheeless' Textbook of Orthopedics  [On-line], Available:  http://medmedia.com/oa4/10.htm (January 25, 2000).

    Miller, M. R. (1999).  Lytic Paget Disease as a Cause of Orbital Cholesterol Granuloma  Archives of Ophthalmology, Journals of the AMA  [On-line],  Available:  http://archopth.ama-assn.org.  (January 25, 2000).