Narrator: This is Science Today. The exact
cause of bone death, or osteonecrosis, is still relatively
unknown. But Dr. Jay Lieberman, an assistant professor
of orthopedic surgery at UCLA, says of the twenty
thousand new cases of hip osteonecrosis each year,
certain risk factors - such as trauma, the use of
steroids or alcohol abuse - seem to be associated.
Lieberman: There are other diseases that are
associated with it also - lupus, rheumatoid arthritis,
Crohn's Disease. Some people think there's a high
risk if you have diabetes mellitus.
Narrator: Lieberman says not knowing the exact
cause and natural history of the disease is one of
the major problems in treating osteonecrosis.
Lieberman: And what I mean by natural history
is, we don't know how many people are walking around
with osteonecrosis of the hip who never become symptomatic.
Even when we talk about patients who take steroids
or patients who have problems with alcohol abuse or
these other diseases - the vast majority of these
patients never develop osteonecrosis. So in general,
we most often pick it up because a patient starts
complaining of hip pain.
Narrator: For Science Today, I'm Larissa Branin.