Osteonecrosis is a problem caused by a short-term or
permanent loss of blood supply to the bone. When blood doesn’t get to bones
they begin to break down, weaken, and eventually collapse. Osteonecrosis is
also called avascular necrosis or “AVN,” “aseptic necrosis, or ischemic bone
necrosis.
Am I at Risk?
Survivors who received bone marrow, cord blood, or stem cell
transplants, as well as those who received corticosteroids (such as prednisone
and dexamethasone) during cancer treatment are at risk for osteonecrosis.
Risk is even higher if you also had:
- high doses of radiation to weight-bearing bones,
- treatment with radiation prior to 1970,
- age older than 10 years at treatment,
- sickle cell disease,
- radiation to the whole body,
- transplant from someone other than yourself, or
- prolonged treatment with corticosteroids for
graft-versus-host disease.
What Are the Symptoms of Osteonecrosis?
Osteonecrosis is most likely to occur during cancer treatment.
But it sometimes happens after treatment ends. It can be disabling, depending
on what part of the bone is affected, how large an area is involved, and how
well the bone rebuilds itself. If it progresses, it can lead to pain and
arthritis.&
It can occur in any bone, but most often affects the ends of
long bones, such as the thigh bone, causing hip and knee problems. If it occurs
near a joint, the joint can collapse. Other common sites are the bones of the
upper arms, shoulders, and ankles. It can occur in one bone, but most often
occurs in a few at one time.
People with osteonecrosis may not have any symptoms at
first. But as the disorder progresses, most will have some joint pain. The pain
may start when you put weight on the bone or joint, but in time it may hurt
even at rest. It may become severe enough to limit movement in the affected
joint. How long between the first symptoms and loss of joint function varies by
person and ranges from months to years.
How Is Osteonecrosis Diagnosed?
A number of tests can be done to diagnose osteonecrosis.
- X-ray is often the first test to help
distinguish osteonecrosis from other causes of bone pain, such as fracture. But
x-rays may appear normal in the early stages of the condition. X-rays are also
used to monitor the course of the condition.
- MRI can detect osteonecrosis in the earliest
stages, when symptoms are not yet present.
- Bone scans are sometimes used to diagnose
osteonecrosis. They are useful because a single scan can show all the areas in
the body that are affected. But they can’t detect it at the earliest stages.
- CT scans provide a 3-D image of bone and can
help see the extent of bone damage.
What If I Have Osteonecrosis?
The goals of treatment for osteonecrosis are to improve use
of the affected joint, reduce pain, stop bone damage, and ensure the joint
lives. Factors that will affect your treatment include your age, whether the
condition is in the early or late stage, the location and amount of bone affected,
and the status of your cancer treatment.
Conservative Treatment
One or more conservative treatments may be used. They include:
- medicine – to reduce pain;
- reduced weight bearing – to slow the damage and
promote healing. Crutches may be used;
- range of motion exercises – to keep joints
flexible, maintain movement, and increase circulation to promote healing and
relieve pain; and
- electrical stimulation – to induce bone growth.
Surgical Treatment
Because conservative treatments may not provide lasting improvement,
some people need surgery to repair or replace the joint, such as these.
- Core decompression – this procedure removes the
inner layer of bone to reduce pressure within the bone and create an open area
for new blood vessels to grow. It works best in the early stages of
osteonecrosis and should help relieve pain and promote healing.
- Osteotomy – in this surgery bone is taken out so
that the tissue without blood supply bears less weight than a nearby healthy
area.
- Joint replacement – the affected bone is taken
out and replaced with an artificial joint.
In addition to conservative and surgical treatment, you can
help manage osteonecrosis by following these tips:
- Avoid activities that put a lot of stress on
your joints, such as running, jumping, football, and soccer. Instead, try
sports that are good for joints with osteonecrosis, such as swimming and
biking.
- Be consistent with recommended exercises.
- Rest your joints when they hurt.
- Let your health care team know if your symptoms
change.
- Take pain or anti-inflammatory medicine as
prescribed.
Where Can I Find More Information?
You can find more information on osteonecrosis from these
organizations: