Paget's Disease
Paget's Disease is a condition where the remodelling of bones
is abnormal, resulting in deformity, pain and fragile bones.
Normal bone is a living tissue which is constantly altered
throughout life - the bone is broken down by one type of cell
(osteoclasts) and then built up again by another (osteoblasts).
In Paget's Disease this remodelling
process is accelerated and newly formed bone has less time
to become structurally organized, and is therefore weaker.
Paget's Disease is a condition which usually affects people
over the age of 50, and is slightly more common in men than
in women. It is particularly common in the UK and Australia
but the incidence world wide is not known. The cause is still
uncertain but includes having a genetic predisposition. Another
event, perhaps later in life, may then start off the disease.
What are the symptoms?
Paget's Disease can affect any bone but it is most common
in the skull, pelvis and leg bones. The bones may become deformed,
for example the long bones may become bowed or the skull may
become larger. Because the bone structure is abnormal the
bones may be painful and are more likely to fracture.
How can Paget's Disease be diagnosed?
Instead of new bone being laid down in neat parallel rows,
in Paget’s disease it has a disorganized structure and
this can easily be seen on X-Rays of the affected bones.
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Xray of bone showing Paget's Disease |
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Xray of normal bone |
How is it treated?
The management of this condition has been revolutionized
by the introduction of bisphosphonates. These drugs inhibit
the activity the osteoclasts.
Currently in the UK the two bisphosphonates in clinical use
are oral risedronate and intravenous pamidronate or zoledronate.
Risedronate is given over a two month period and needs to
be taken fasting because bisphosphonates are badly absorbed
from the gut.
For those patients in whom there is a problem with oral treatment
(the bisphosphonates as a group may cause heartburn or indigestion)
the drugs can be given as an intravenous infusion. While oral
treatment can be given by your General Practitioner, the intravenous
infusion needs a hospital out-patient visit.
Treatment usually controls both the symptoms and the abnormal
bone remodelling and may last for several months before another
course is needed. There is uncertainty whether the best approach
is to give enough bisphosphonate to control symptoms alone
or whether it is best to reduce bone remodelling to within
the normal range and this issue is currently being studied
in the PRISM
trial run by the University of Aberdeen.
Questions patients ask
Why is my affected bone painful?
Because the increase in size of the affected bone stretches
nerve fibres over the surface and this causes pain. Paget’s
disease also increases the wear and tear of major joints that
occurs in all of us as we age and this may also cause pain.
Will my Paget’s disease spread from one bone
to another?
No. The disease will spread within an affected bone
but this can be prevented by treatment. Pagets disease never
moves from an affected to a non-affected bone.
More information
National Association
for the Relief of Paget's Disease
The Paget Foundation
The Arthritis Society
Arthritis
Research Campaign
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