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Healthy living after treatment for childhood cancer Osteonecrosis
What is osteonecrosis?
Osteonecrosis is a disorder resulting from a temporary or permanent loss of bloodsupply to the bone. Blood carries essential nutrients and oxygen to the bones. Whenthe blood supply is disrupted, the bone tissues (osteo) begin to break down (necrosis).
This can weaken the bone and eventually result in its collapse. If this occurs near ajoint, it can lead to the collapse of the joint surface, resulting in pain and inflammation(arthritis). Osteonecrosis is also referred to as avascular necrosis or "AVN", "asepticnecrosis", and "ischemic bone necrosis". Osteonecrosis can occur in any bone, but most commonly affects the ends (epiphysis)of long bones such as the thigh bone (femur), causing hip and knee problems. Othercommon sites include the bones of the upper arms, shoulders, and ankles.
Osteonecrosis can occur in a single bone, but more commonly occurs in several bonesat one time (multifocal osteonecrosis).
Osteonecrosis can sometimes be disabling, depending on what part of the bone isaffected, how large an area is involved, and how well the bone rebuilds itself. Normalbone continuously breaks down and rebuilds itself. This process keeps the bonesstrong. Osteonecrosis is the result of bone tissues breaking down faster than the bodycan repair them. If the disorder progresses, it can lead to pain and arthritis. What causes osteonecrosis?
Osteonecrosis is caused by interruption of the blood supply to the bone. If bloodvessels are blocked with fat, become too thick or too small, or get too weak, they maynot be able to provide the amount of blood necessary for the bone tissue to survive. What are the risk factors for osteonecrosis?
Corticosteroids (such as prednisone and dexamethasone) given during cancertreatment can affect the bone and blood vessels, resulting in osteonecrosis. People whohave undergone hematopoietic cell transplant (bone marrow, cord blood, or stem celltransplant) are also at risk for developing osteonecrosis. Other factors that increase therisk of osteonecrosis in people who received corticosteroid therapy or hematopoieticcell transplant (HCT) include treatment with high doses of radiation to weight bearingbones, treatment with older radiation approaches (before 1970), being older than 10 atthe time of treatment, having sickle cell disease, receiving total body irradiation (TBI), Copyright 2008 Children’s Oncology Group Health Link
Healthy living after treatment for childhood cancer undergoing an allogeneic transplant (from someone other than yourself), and havingprolonged treatment with corticosteroids for chronic graft-versus-host disease followingHCT. Osteonecrosis is most likely to occur during the time that cancer is being treated,but it can also sometimes happen after completion of cancer therapy. Steroids and osteonecrosis
Corticosteroids (such as prednisone and dexamethasone) are commonly used fortreatment of many cancers, such as leukemia and lymphoma. Dexamethasone is alsosometimes used for treatment of nausea and vomiting associated with chemotherapyand to control brain swelling. There is no clear explanation as to how corticosteroidscause osteonecrosis, but it is believed that they may interfere with the body’s ability tobreak down fatty substances. These substances can clog the blood vessels, causingthem to narrow. This reduces the amount of blood that gets into the bone. What are the symptoms of osteonecrosis?
People in the early stages of osteonecrosis may not have any symptoms. However, asthe disorder progresses, most people will experience some joint pain. At first, theperson may only experience pain when bearing weight on the affected bone or joint. Asthe disorder progresses, symptoms may be present even at rest. Pain may developgradually and its intensity can range from mild to severe. If osteonecrosis progresses and the bone and surrounding joint surfaces collapse, thepain can increase considerably and may become severe enough to limit movement inthe affected joint. The period of time between the first symptoms of osteonecrosis andthe loss of joint function is different for each person and ranges from several months toyears. How is osteonecrosis diagnosed?
An x-ray is usually the first test to be done when osteonecrosis is suspected. It can help
distinguish osteonecrosis from other causes of bone pain, such as fracture. In the early
stages of osteonecrosis, an x-ray may appear normal, so other tests may need to be
done to establish the diagnosis. Once the diagnosis has been made, and in the later
stages of osteonecrosis, x-rays are useful in monitoring the course of the condition.
MRI is one of the most useful tools in diagnosing osteonecrosis because it 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 one scan can
show all the areas in the body affected by osteonecrosis. However, bone scans do not
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Healthy living after treatment for childhood cancer detect osteonecrosis at the earliest stages. A CT scan provides a three-dimensional
image of the bone and can be useful in determining the extent of bone damage.
Surgical procedures such as a bone biopsy can conclusively diagnose osteonecrosis,
but are not commonly done.
How is osteonecrosis treated?
The goals of treatment for osteonecrosis are to improve the person’s use of the affectedjoint, reduce pain, stop bone damage, and ensure joint survival. Treatment can beconservative or surgical. In order to decide the best treatment for a patient, thefollowing factors are considered: The stage of the disorder (early or late) The location and the amount of bone affected (small or large) The status of cancer and cancer treatment Conservative treatment
Medication - to reduce pain
Reduced weight bearing - to slow the damage and promote natural healing.
Crutches may be recommended to limit weight or pressure on the affected joint.
Range of motion exercises – to keep the joints flexible. This is also important to
maintain movement and increase circulation in the joints. This can promote healing
and may relieve pain. Physical therapists can teach the correct exercises.
Electrical stimulation - to induce bone growth
Conservative treatments may be used alone or in combination, but they may not pro-vide lasting improvement. Some people may require surgery to permanently repair orreplace the joint.
Surgical Treatment
Core decompression – is a surgery that removes the inner layer of bone. This
may reduce pressure within the bone and create an open area for new blood vessels
to grow. Sometimes a piece of healthy bone with good blood vessels (bone graft)
is put in this area to speed up the process. This procedure works best in the early
stages of osteonecrosis and should help relieve pain and promote healing.
Osteotomy – is a surgery that involves taking out a piece of bone, usually a
wedge, to reposition the bone so that the tissue lacking blood supply (avascular
area) bears less weight than an adjacent healthy area.
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Healthy living after treatment for childhood cancer Arthroplasty – is also referred to as joint replacement. The affected bone is
removed and replaced with an artificial joint. This treatment may be needed in the
late stages of osteonecrosis and when a joint is destroyed.
Health Promoting Behaviors/Interventions
Avoid activities that put a lot of stress on your joints. Activities that stress the joints include running, jumping, football, soccer, volleyball, basketball and similarsports. Activities that are good for joints with osteonecrosis are swimming and bicycling.
Be consistent with recommended exercises.
Let your healthcare provider or physical therapist know if there are any changes in your symptoms.
Take pain or anti-inflammatory medications as prescribed.
Resources:
National Institute of Arthritis and Musculoskeletal and Skin Diseases
National Institutes of Health, 1 AMS Circle, Bethesda, MD 20892-3675
Phone: 301-495-4484 or 877-226-4267 (toll free), TTY: 301-565-2966
Fax: 301-718-6366. Web: www.niams.nih.gov/hi/topics/osteonecrosis/index.htm
American Academy of Orthopaedic Surgeons
P.O. Box 2058, Des Plaines, IL 60017
Phone: 800-824-2663 (toll free). Web: www.aaos.org
Adapted by Katherine Myint-Hpu, MSN, MPH, PNP, Georgetown University Hospital,Washington, D.C., from "Health Topics: Questions and Answers about AvascularNecrosis" by the National Institute of Arthritis and Musculoskeletal and Skin Diseases,January 2001, and "Avascular Necrosis – Do You Know" by St. Jude Children’sResearch Hospital, used with permission. Reviewed by Neyssa Marina MD, Joan Darling PhD, Melissa M. Hudson MD, SmitaBhatia MD, MPH, and Sarah Bottomley MN, RN, CPNP, CPON®. Copyright 2008 Children’s Oncology Group Health Link
Healthy living after treatment for childhood cancer Additional health information for childhood cancer survivors is available at Note: Throughout this Health Links series, the term "childhood cancer" is used to designate pediatric cancers that may
occur during childhood, adolescence, or young adulthood. Health Links are designed to provide health information
for survivors of pediatric cancer, regardless of whether the cancer occurred during childhood, adolescence, or young
adulthood.
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Source: http://www.survivorshipguidelines.org/pdf/Osteonecrosis.pdf