P

Paget’s disease of the bone A rare and some-
times hereditary condition in which the process of
BONEremodeling sporadically accelerates. The new
bone that forms to replace old bone has increased
mass, enlarging the bone structure, though is
weaker than normal bone. Paget’s disease of the
bone affects bones randomly throughout the body.
Most often affected are the spine, hips, legs, and
cranium (skull). Paget’s disease of the bone is
more common in people over age 40 and affects
men and women about equally. Some researchers
believe Paget’s disease of the bone is genetic and
other researchers believe a VIRUSactivates it.

Symptoms and Diagnostic Path
It is not uncommon for someone to be unaware
he or she has Paget’s disease of the bone until sev-
eral bone fractures occur. Other people have obvi-
ous abnormalities of the spine, bowed legs, and
moderate to severe JOINT PAIN and bone pain.
When there is family history of Paget’s disease of
the bone the doctor may look in that direction for
diagnosis. When there is not, doctors tend to first
explore more common causes for similar symp-
toms (such as OSTEOPOROSIS). The diagnostic path
then becomes circuitous, and diagnosis may take
quite some time.
BLOOD tests to measure the presence of an
enzyme, alkaline phosphatase, suggest a disorder
of bone growth when the enzyme is present.
Alkaline phosphatase levels in the body rise
whenever there is new bone growth activity.
Though not diagnostically conclusive, elevated
alkaline phosphatase further points in the direc-
tion of Paget’s disease of the bone. COMPUTED
TOMOGRAPHY (CT) SCAN and MAGNETIC RESONANCE
IMAGING(MRI) can show the extent to which the
dysfunctional remodeling affects bones through-

out the body. The pattern of bone damage is char-

acteristic.

Treatment Options and Outlook

Treatment for Paget’s disease of the bone targets

both bone loss and symptoms such as pain. Med-

ications to slow bone resorption (osteoclast activ-

ity) help retain more normal bone structure.

Among these medications are CALCITONIN and

the bisphosphonates (alendronate, clodronate,

etidronate, pamidronate, risedronate, and tilu-

dronate). ANALGESIC MEDICATIONSand NONSTEROIDAL

ANTI-INFLAMMATORY DRUGS (NSAIDS), in over-the-

counter or prescription products, may be neces-

sary to relieve pain.

Risk Factors and Preventive Measures

The primary risk factor for Paget’s disease of the

bone is a family history, known or suspected, of

the condition. Though there are no measures to

prevent Paget’s disease of the bone, early diagnosis

offers the best opportunity to mitigate bone loss

and other symptoms.

See also BONE CANCER; CALCIUM AND BONE HEALTH;

GENETIC DISORDERS; OSTEOGENESIS IMPERFECTA; OSTEO-

MALACIA.

palmar fibromatosis See CONTRACTURE.

patellofemoral syndrome Pain at or around the

patella (kneecap) that often is worse when walk-

ing or running downhill or going down steps.

Many people also experience the same kind of

pain when sitting with the knees bent for a pro-

longed time. Doctors believe patellofemoral syn-

drome results from a combination of factors that

include anatomy (individual variations in the

structure of the knee), biomechanics (the function

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