Paget's Disease

CHECK-UP: My dad has had pains in his hip and leg for some time. When he eventually went to his GP, he was diagnosed with Paget’s disease. What is this?

Paget’s disease is a chronic disease of the bones. It is estimated to affect about 3-4 per cent of the population over the age of 50. The condition is more likely to affect the spine, pelvis, long bones of the limbs, and skull and is slightly more common in men than women.

In normal bone, a process known as “remodelling” takes place in response to normal wear and tear. This involves old bone being absorbed by cells called osteoclasts, while new bone is reformed by other cells called osteoblasts.

In Paget’s disease, osteoclasts are more active than osteoblasts, which lead to more bone absorption than normal. In response, the osteoblasts create excess bone that is enlarged and misshapen. This new bone is fragile and brittle and is more likely to break.

Is bone pain the only symptom?

Many people with Paget’s disease experience no symptoms with the condition only picked up when an X-ray or routine blood test is performed for another reason. Bone pain is the most common complaint and can be the result of the disease activity or as a result of complications.

Complications can include fractures, deformity of bone, arthritis in joints near affected bone or nerve compression from enlarged bones. In a minority of sufferers, symptoms of fatigue, weakness, abdominal pain or lack of appetite may be caused by elevated levels of calcium in the blood, due to the disease process.

Although medications such as painkillers, non-steroidal anti-inflammatory drugs and drugs called bisphosphonates that slow the rate of bone turnover can help symptoms, there is as yet no treatment that reverses the effects on the bone.

What are the chances of other members of the family developing it?

Paget’s disease tends to run in families and may be found in 25-40 per cent of the relatives of someone with the disease. It is also more common in those of Anglo-Saxon descent and those who live in Western Europe, the US, Australia and New Zealand.

Environmental factors as well as genetic factors may be involved in its development. Medical treatments can help decrease the symptoms of Paget’s disease, but there is no known way to reverse the effects on the bone. In severe cases, surgery may be required to treat complications.