A disorder of bone maintenance and repair, leading to weakened, distorted, and occasionally painful bones
In a healthy person, bone is continually being broken down and replaced by new bone to maintain the normal bone structure. However, in Paget’s disease of the bone (also known as osteitis deformans), the processes involved in the normal breakdown and replacement of bone tissue become disrupted in some parts of the skeleton. The condition may affect any bone in the body, but the pelvis, collarbone, vertebrae (bones of the spine), skull, and leg bones are those most commonly involved. The affected bones become larger and structurally abnormal, which progressively weakens them and makes them more liable to fracture.
Paget’s disease usually develops after the age of 50 and affects 1 in 10 people over the age of 80. The disorder tends to run in families and affects more men than women. Paget’s disease is most common in Europe, North America, and Australia. It is rare in people of Asian and African origin.
Frequently, Paget’s disease produces no symptoms and may be diagnosed only by chance when an X-ray has been taken for some other reason. If symptoms are present, they may include:
Bone pain that is worse at night.
Joint pain, especially in those joints near affected bones.
Bone deformities, such as bow legs or enlargement of the skull.
Fractures that occur after a minor injury.
Long-standing Paget’s disease may also lead to the following complications:
Numbness, tingling, or weakness in the affected area if the bone presses on adjacent nerves.
In rare cases, a further complication of Paget’s disease is the development of a type of bone cancer (see Primary bone cancer).
If your doctor suspects you have Paget’s disease, he or she may arrange for you to have X-rays to confirm the diagnosis. You may also have blood and urine tests to check for abnormal levels of substances involved in the formation and breakdown of bone. If your hearing is affected, you will probably have hearing tests.
Treatment is not necessary if you have no pain or other symptoms and are unlikely to be at risk of fractures. If you are in discomfort, your doctor will prescribe painkillers or a nonsteroidal anti-inflammatory drug. If these drugs are inadequate then specific treatment may be needed. The most common treatment is with bisphosphonates; less commonly, the hormone calcitonin may be prescribed (see Drugs for bone disorders). Your response to these drugs may be monitored by blood tests.
Although drug treatment will not reverse any bone deformity that may have already developed, it will slow the progress of the disease.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.