Avascular necrosis (AVN) or Osteonecrosis (ON), is a very serious bone disorder in which the affected bones or joints actually die. This is a secondary disease that can result from a variety of things: from "the bends" (scuba diving variety), to corticosteroid usage, lipid storage diseases, pregnancy, alcohol consumption, post fracture or trauma to a bone among other causes.
The drug prednisone is a corticosteroid used in some types of lymphoma chemotherapy. It can cause a restriction of blood supply to the larger bones in the body, particularly the hips, knees, and shoulders. If you happen to be one of the unlucky individuals who has this reaction, you can develop Avascular Necrosis. Untreated conditions can result in a need for total hip replacements or other serious measures.
If you are aware of increased pain and stiffness in the hips
during chemotherapy, an MRI scan or possibly x-rays can indicate development of AVN. Regular x-ray may not show any indications of the problem until it reaches advanced stages.
The progression of AVN is broken down into 5 main stages which are usually diagnosed by x-rays and MRI studies. Your physician may elect to also order other tests such as specialized blood tests, CT scans or nuclear medicine bone scans for additional information. The staging of AVN is based upon the amount of bone destruction that is revealed on x-rays or MRIs. Note: this staging for AVN is totally different than your staging for lymphoma:
Stage I: The routine x-rays are normal but the MRI is abnormal indicating bone death (osteonecrosis).
Stage II: The routine x-rays remain normal (in late Stage 2 a small darker area (radiolucency) maybe seen) and the MRI demonstrates increased osteonecrosis and hardening (sclerosis) of the outside (cortex) of the bone.
Stage III: The x-rays and MRI reveal a crescent sign (crescent moon shape) of the femoral head, but the shape (contour) of the femoral head remains normal.
Stage IV: The x-rays and MRI reveal flattening or the collapse of the femoral head.
Stage V: The x-rays and MRI reveal degenerative joint disease in the affected joint.
Early stages of the condition can sometimes be remedied by a surgical procedure called core decompression. This procedure involves drilling out the dead bone, with the outcome being regrowth and establishment of new blood vessels and healthy bone. If the procedure works, the need for surgery such as hip replacement is postponed or eliminated.
The Prednisone information page
Information on Magnetic Resonance Imaging (MRI) scans
The Avascular Necrosis (AVN) Support Group International Home Page
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) presents the list of questions and answers on AVN
The Johns Hopkins University Center for Osteonecrosis Research and Education
The osteonecrosis group is a mailing list on Yahoo. It is great.
For more information on Adult Lymphomas:
Adult Hodgkin's Disease Chemotherapy
Adult Non-Hodgkin's Disease Chemotherapy
For more information on Childhood Lymphomas:
Childhood Hodgkin's Disease Chemotherapy
Childhood Non-Hodgkin's Lymphoma Chemotherapy
Other pages of interest:
The Lymphoma Information Network
NEW: The Official Patient's Sourcebook on Avascular Necrosis by Icon Health Publications, James N. Parker
Coping With Prednisone: (and Other Cortisone - Related Medicines): It May Work Miracles, but How Do You Handle the Side Effects by Eugenia Zukerman and Julie R. Ingelfinger MD - More Information