Paget’s disease of bone is a relatively common condition in older people; in fact, it is the second most common type of bone disease after osteoporosis. It affects the process of bone renewal, where the body absorbs old bone and makes new bone, and can cause abnormalities to form, most commonly in the skull, spine, pelvis and thighs.
There are other types of Paget’s, however the bone disease is by far the most common, so is often simply referred to as “Paget’s disease” (as it will be in this article).
What is Paget’s disease?
Throughout our lives, our bones are renewed and repaired via “bone remodelling”; osteoclast cells break down old and damaged bone, and osteoblast cells lay down new material that mineralises over time to form strong replacements. In Paget’s disease, bone is broken down faster than normal, meaning that new bone has to be laid down faster. This increased process rate affects the structure of the newly-formed bones and can cause abnormalities, such as them being weakened, misshapen or enlarged. It can appear in any bone, and in multiple locations.
What causes Paget’s disease?
Paget’s disease occurs because of unusually large osteoclast cells. It is believed that their presence may be due to genetic factors – that there is an inherited gene variation that affects the development of those cells. Abnormalities in the predisposing gene have been identified in up to 50% of people who have a family history of the disease; those with this family history are thought to be seven times more likely to develop it.
It is also thought that there may be environmental factors at work; it has been found that both the severity and frequency of Paget’s has decreased over the past 25 years, however researchers have not yet isolated the factors that may be affecting it.
What are the risk factors for Paget’s disease?
The risk of developing Paget’s disease increases with age, and is rare in those under 50; up to 5% of those 55 and over in the UK are thought to have it. As stated above, your risk is also higher if you have a family history of the disease. It is found more commonly in men than in women, and is more prevalent in those of European descent.
The disease is unavoidable and incurable for those who have it, but is treatable and manageable.
Signs and symptoms in the elderly
In many cases, those with Paget’s disease have no idea that they have it – symptoms and complications do not manifest for everyone, or may be mistaken for other issues such as arthritis. For a lot of people, it is only discovered by chance during x-rays or blood tests being undertaken for other reasons.
Bone pain is the most common symptom for those who get them, and is characterised by a deep, dull, constant ache that is worse at night. An increase in blood flow to the affected areas can also cause a feeling of “warmth”, or redness of the skin.
Joint pain can be a result of abnormal bone growth; cartilage that protects the bones can become damaged as it tries to accommodate the change in shape and size. This can lead to pain, tenderness, stiffness or swelling in the joints.
**Nerve issues **can also occur since many of our major nerves run alongside, or even through, our bones. The rapid shifting of growth can end up compressing or pinching the nerves which can lead to shooting pains through the affected area and beyond, numbness or tingling, or partial loss of movement in the affected limbs.
Paget’s disease can have other effects on the body beyond the above symptoms. The newly-formed bone is softer and more fragile, meaning that fractures or breaks may be more common. They can also grow misshapen or enlarged, or bend easily due to being weaker, which can lead to bow legs, or scoliosis/kyphosis in the spine, or osteoarthritis due to the extra stress placed on joints. Alternatively, growth in the skull can lead to hearing loss, headaches, vertigo or tinnitus.
In rare cases, Paget’s disease can cause hypercalcaemia, a build-up of calcium in the blood which causes drowsiness, depression, tiredness or constipation; or heart failure as too many blood vessels in the new bone make it harder for the heart to pump blood around the body. The rarest complication is osteosarcoma, a type of bone cancer which manifests with similar symptoms (bone pain, swelling) in roughly 1:1000 people. Thankfully, if caught early enough, it is treatable.
Symptom management and care
Assessment and diagnosis
In most cases, Paget’s disease is discovered by accident during tests for other issues. If Paget’s is suspected, then the first step is an assessment with a consultant, who will look at any symptoms and family history, and give an initial physical exam.
If further examination is necessary, it is done with imaging (X-rays or bone scans) and blood tests. X-rays are the most common method of discovery, easily showing bones that have become misshapen or enlarged. A bone scan involves the injection of a small amount of radioactive tracer into the body, which collects in the bones and can then be imaged with a gamma camera. They may also do a blood test; those with Paget’s usually have an excess of the enzyme alkaline phosphatase in their blood, although this can be caused by other issues.
More tests, such as a bone biopsy, or CT/MRI scans, may be ordered if severe signs of the disease are found.
Treatment with medicines
One of the most common treatments is with bisphosphonates, either orally or by injection. These are medicines that help regulate bone growth by affecting the osteoclast cells to reduce their bone resorption levels. There are several different types of bisphosphonates; the current best of these is zoledronate, as not only does it help to relieve pain, but is the most potent and lasts the longest, with one intravenous treatment being effective for several years.
If you are unable to take bisphosphonates, then you may be prescribed calcitonin instead. This is a naturally occurring hormone involved in bone regulation, and can be administered nasally or via injection, but needs to be taken regularly.
If the symptoms include pain, then over-the-counter painkillers, or something stronger if prescribed, can help alleviate them.
Lifestyle and supportive therapies
It is important that those with Paget’s get enough vitamin D and calcium to strengthen their bones. Taking supplements and eating certain foods, such as dairy and fish, can help with this.
Exercising regularly and protecting yourself against falls is useful to help keep joints supple and reduce the risk of complications. Some people may also benefit from physiotherapy, or physical support like walking sticks or braces, to improve movement and reduce the pressure placed on the bones.
Surgery should only be needed if further complications arise, such as for helping fractures to heal, for joint replacements, or to move a bone away from a pinched nerve. In cases of extreme deformities forming, an osteotomy may be needed in order to realign or cut and straighten misshapen bones.
It may sound intimidating, but the truth is that although Paget’s disease is incurable, it is perfectly treatable and manageable, especially if it is found before any major bone changes occur.
At SuperCarers we help families connect with compassionate and vetted carers in their local area. Get in touch on 020 8629 1030 and we’ll give you expert advice on the types of home care available and all the steps required to find a suitable carer for yourself or a family member.
Find out more about how to keep your bones strong as you age.