What is Paget’s Disease?

Paget’s disease is a chronic bone disease involving abnormal bone remodeling processes. While healthy bones constantly “remodel” themselves by creating new bone to replace old bone, bones affected by Paget’s disease produce new bone too rapidly, causing fragile, misshapen bones prone to fractures. In advanced stages of Paget’s disease, bone composition resembles connective, fibrous tissue containing blood vessels. Paget’s disease commonly affects the legs, spine, skull, and pelvis, although it can impact any bone in the body.

Symptoms of Paget’s Disease

The weaker, softer bones of individuals with Paget’s disease cause chronic bone pain, stress or hairline fractures without trauma, and physical deformity. Symptoms depend on where the disease is impacting bones. Pelvic bones affected by Paget’s disease produce radiating pain across the pelvis and lower back while numbness, tingling, and pain in a leg or arm may mean Paget’s disease is deteriorating the spine. Bone overgrowth in the skull causes headaches and hearing loss due to nerve compression. Paget’s disease in the leg may deform bones by forcing them to enlarge and bend. When leg bones become misshapen and can no longer provide support for the body, knee and hip joints may develop osteoarthritis due to this extra stress.

Is Paget’s Disease Hereditary?

In many cases, yes. Two genes called RANK and SQSTM1, along with areas of chromosomes five and six, are associated with the development of Paget’s disease. However, people can also develop Paget’s disease without a genetic link. About 40 percent of people who inherit Paget’s disease have one mutation on the SQSTM1 gene. This gene encodes the p62 protein involved in bone cell function. Paget’s disease is also associated with RANK mutations. RANK is an acronym for “Receptor Activator of Nuclear Factor KB. This membrane protein is expressed on surfaces of osteoclasts, or bone cells that decompose bone tissue.

Complications of Paget’s Disease

Osteoarthritis is the most common complication of Paget’s disease, resulting from changes to the shape of a bone that alters skeletal mechanics. If a femur bone bows due to Paget’s disease, distortion of the leg’s alignment causes abnormal stress on the knee joint and degeneration of joint components. Other complications include:

Heart failure

malformed bones coupled with the emergence of abnormal blood vessels may force the heart to pump harder to maintain adequate circulation of blood throughout the body.

Kidney stones

Paget’s disease can affect the pelvis.

Nervous system

Nerve compression and decreased blood flow to the spinal cord and brain may produce signs of neurological damage.

Jaw bone infection

Facial bones affected by Paget’s disease can cause loosened teeth, chewing disturbances and severe dental issues that could promote jaw bone infections.

Angioid streaks

Small cracks in a retinal membrane could become calcified. Streaks may diminish vision if they extend to the fovea and retinal pigment epithelium.

Non-Hereditary Cause of Paget’s Disease

In people without genetic markers for Paget’s disease, the bone disorder is thought to emerge following a “slow virus” infection that remains undetected in the body for many years. Viral infections associated with the development of Paget’s disease include measles, respiratory conditions, and meningitis. Slow virus infections have long incubation periods, are asymptomatic, and re-emerge from latency if the individual develops a health issue that compromises the immune system.

How Do Doctors Diagnose Paget’s Disease?

Doctors may use a variety of diagnostic tests to confirm Paget’s disease, including x-rays that show deformities of affected bone, blood tests to indicate elevated levels of alkaline phosphatase, and bone scans. Finally, urine analysis showing bone turnover markers such as pyridinoline and hydroxyproline, two substance released by abnormal bone remodeling processes.

Treatments for Paget’s Disease

Primary care physicians, endocrinologists, rheumatologists, orthopedists, and neurologists can detect and determine treatment for Paget’s disease. Medications are the first line of treatment for addressing bone pain, nerve compression pain, and slowing the progression of the disease. When only mild symptoms are present, doctors may not prescribe medications until symptoms begin interfering with a person’s ability to perform daily activities. In some cases, people with Paget’s disease may need surgery to expedite healing of fractures, replace worn-out joints damaged by osteoarthritis, realign malformed bones, and remove pressure from nerves.

Bisphosphonates and Paget’s Disease

People with moderate to severe symptoms of Paget’s disease are routinely prescribed bisphosphonates. This help prevent loss of bone density and are often prescribed to treat osteoporosis and other diseases affecting bone health. Doctors may also prescribe an intravenous infusion of zoledronic acid (one dose every two years) for people in whom the disease is dormant but detected through diagnostic testing.

What is the Prognosis for People with Paget’s Disease?

Rarely fatal, Paget’s disease presents a good prognosis as long as individuals receive treatment before major bone damage and deformation occurs. Early diagnosis is vital to minimizing complications that could lead to serious health issues such as cardiovascular problems. Although medication is highly effective at addressing symptoms, no cure exists for Paget’s disease. Fewer than ten percent of people with Paget’s disease develop osteosarcoma. This rare bone cancer requires chemotherapy, radiation therapy, surgery, or a combination.

Lifestyle Changes and Paget’s Disease

In addition to taking medication as prescribed, people with Paget’s disease should spend at least an hour a day in the sun to obtain enough vitamin D. Regular exercise is also important for supporting bone health, reducing weight gain and maintaining joint flexibility. Doctors can assist individuals in developing exercise programs that do not place excess stress on joints. Finally, people with actively symptomatic Paget’s disease should try to remain as mobile as possible to counteract the progression of the disease.

More Facts about Paget’s Disease

Paget’s disease and osteoporosis are the most common bone disorders, affecting people in all areas of the world.

Symptoms of Paget’s disease are rare in men and women younger than 55. Prevalence of Paget’s disease increases as a person reaches their 60s and 70s.

Only about three percent of individuals younger than 40 years old are diagnosed with Paget’s disease.

More men than women have Paget’s disease.

Paget’s disease particularly affects individuals of European descent. It is rare for Indian, Asian and African people to have the condition.

Children whose relatives have Paget’s disease can undergo genetic testing to look for evidence of the disease.