Regrowing Bone Q&A

What is osteonecrosis?

Dr. Lieberman: Osteonecrosis is when the blood supply to the femoral head is jeopardized in some way leading to the death of bone cells. Necrosis means death. Osteo means bone. So it’s really “death of bone” in the femoral head.

Do you know what causes that?

Dr. Lieberman: We don’t know the path of physiology exactly, but we do know that osteonecrosis is associated with certain risk factors.

What are those risk factors?

Dr. Lieberman: The risk factors include steroid use, such as prednisone, alcohol abuse, trauma, patients with lupus or rheumatoid arthritis or other inflammatory diseases, patients with sickle cell anemia, Gaucher’s disease, Crohn’s disease — these are all diseases associated with this problem.

Do you see it any more often in older people than young people, or does it hit any age?

Dr. Lieberman: It’s more commonly seen in the younger patients, and this is particularly because these are the patients who most often get into accidents where they jeopardize the blood supply to the femoral head. Of these are the patients who most often take steroids.

Are there any early symptoms?

Dr. Lieberman: The problem with diagnosing the disease is that the symptoms are sometimes mistaken for a muscle pull or something like that because the patients will complain of pain in the groin or pain in the buttock. This can be confused with the discomfort of a muscle pull, especially if you’re playing sports. This is often the first sign.

How do you diagnose it?

Dr. Lieberman: Diagnosis can be made by plain films. In many cases, you can see sclerosis of the femoral head or actually collapse of the femoral head. In many cases, we make the diagnosis with an MRI.

Will a screening for osteoporosis pick it up?

Dr. Lieberman: The test for osteoporosis, which is where we look at bone density, is a different study. You’re looking for the amount of mineral in the bone. In the test for osteonecrosis, we’re looking for the viability of the bone in the femoral head. So you’re doing the test for different purposes. We also do the bone density test to look at the femoral neck or the lumbar spine of the distal radius. With osteonecrosis, we actually look at the femoral head specifically, or sometimes it can be seen in the knee or the shoulder joint.

Tell me how this new procedure to regrow bone works.

Dr. Lieberman: We’ve altered some procedures that were used in the past because we now have new tools that may help the patient. Basically what we’re doing is making a hole in the bone — it’s called the core decompression. We then take bone from the patient’s iliac crest or from their greater trochanter, and we place that up into the femoral head. Prior to doing that, we remove part of the dead bone and pack in the new bone. Then we replace it with a capsule containing a protein that induces bone formation. We then follow that with a fibular allograft, which is a piece of bone from the lower extremity taken from a cadaver that was treated with this bone morphogenetic protein, which has actually been freeze-dried onto it, and we place that up the femoral neck.

How have you traditionally treated this disease?

Dr. Lieberman: There are a number of different procedures that are presently available to try to save femoral heads. Total hip arthroplasty is an excellent procedure. However, it was not originally meant for younger patients because it wears out over time. If we do it in somebody 25 or 35, they may require three or four revisions during their lifetime. So the goal is to try to save the femoral head to avoid a total hip replacement.

So is this procedure a permanent fix?

Dr. Lieberman: Right now we don’t have enough data to determine if it’s permanent. Our goal is to delay the need for a total hip arthroplasty as long as possible.

Who is the ideal candidate for this procedure?

Dr. Lieberman: I think the ideal candidate at this time would be young patients between 25 and 45 who do not have a collapsed femoral head and are not taking steroids or do not have a high intake of alcohol.

What about older patients?

Dr. Lieberman: If, for example, you’re a 65-year-old individual who already has a collapse of the femoral head, you’re going to do quite well with the total hip replacement. So there’s no need to try to save the femoral head. The total hip replacement will work well, and it has a good chance of lasting their lifetime.

How common is this disease?

Dr. Lieberman: Approximately 10,000 cases of osteonecrosis are diagnosed each year, and it’s really a matter of how early we pick up the diagnosis. So it could help maybe a third to a half of those people who develop osteonecrosis.