Frequently Asked Questions
What is avascular necrosis of the hip?
Avascular necrosis (AVN) of the hip is an abnormal and possibly crippling condition in which blood cannot get to the hip bone. When the blood supply to the bone is blocked, the area without blood supply can die. This may lead to collapse of the bone requiring replacement with an artificial hip joint. However, if AVN Is recognized in its early stages, it may be possible to reverse this condition and save the hip joint.
How does AVN affect the hip?
A healthy hip joint allows you to walk, squat and turn without pain. A problem hip can interfere with many activities you enjoy. A damaged hip joint, such as one affected by AVN, causes pain and discomfort and limits your ability to walk, run and get around.
What are the signs and symptoms of AVN of the hip?
Signs and symptoms for AVN can often be vague. When it first starts, the condition is usually painless. When the disease progresses, you may find you have pain in the groin, buttock or outer thigh region on the same side of your body as the affected hip. If you experience painful symptoms, you will find they tend to be worse when you stand or walk and better when you rest.
What causes AVN of the hip?
AVN of the hip can be caused by an injury that damages the hip joint. Most causes of AVN, however, are not related to trauma. For example, some patients who are treated with steroids (e.g., prednisone) can develop AVN of the hip. Others who drink excessive amounts of alcohol are at increased risk for developing AVN of the hip. Certain medical conditions such as sickle cell disease or systemic lupus erythematosus are also associated with AVN of the hip. In some cases, there are patients who develop AVN of the hip and no one knows why.
How much alcohol puts me at risk for AVN?
Several alcoholic drinks a day for several years can cause fatty deposits to form in your blood vessels. The fatty deposits can restrict the flow of blood to your bones. The more alcoholic drinks you consume on a daily basis, the higher your risk of developing AVN. Specifically, a daily intake of 5 fluid ounces of wine (one full glass) or one mixed drink appears to be the exposure threshold for alcohol-associated AVN. This means that even if one drink per day may not cause AVN, in most people, it is enough to cause AVN In some people who are more susceptible to the disease.
Susceptible individuals who consume two glasses of wine or two drinks per day are ten times more likely to develop AVN than those who don't drink alcohol.
How Is AVN diagnosed?
The earlier AVN is diagnosed, the more predictable your treatment will be. The best way for your healthcare provider to diagnose AVN Is for you to give a thorough health history. Obtaining the history will be followed by a physical examination, x-rays and imaging studies (e.g., magnetic resonance imaging or MRI).
If you were on steroid medication for a long time, screening for osteoporosis is indicated and moderation of continued use of steroids should be discussed with your doctor. Because AVN of the hip is often associated with other conditions (sickle cell disease, systemic lupus erythematosus), if you have one of these conditions, it Is important that you see a medical doctor who is familiar with treating these diseases. If excessive alcohol use is suspected as the cause of your AVN, it will be helpful for you to discuss this issue with a social worker, a counselor or other professional in the community who can assist you with alcohol abstinence.
Will physical therapy help me?
Physical therapy may provide relief from your symptoms but generally will not prevent AVN from getting worse.
Will staying off my feet help me?
Using crutches or a cane is not helpful in preventing AVN; reducing weight bearing with these assistive devices can at times control these symptoms.
Are there any medications that are helpful?
Ibuprofen, naproxen and other nonsteroidal anti- Inflammatory drugs (NSAIDs) are the most common medications prescribed for relief of discomfort. They do not, however, reverse or delay the progression of AVN. The medication, Alendronate (Fosamax), has been shown to be effective in treating early AVN and preventing or delaying the disease from progressing. However, use of this drug for AVN is not FDA-approved and would be considered an off-label application.
What can I do to prevent getting AVN of the hip?
The three most Important things you can do to prevent AVN are:
- Avoid excessive use of alcohol
- Avoid smoking and
- Take the lowest dose of steroids that Is effective.
If you have AVN, you should similarly abstain from excessive alcohol intake and smoking, and take the lowest possible dose of steroid medication (when indicated). In addition, it is important to manage your weight to avoid placing excessive pressure on your joints.
Will surgery help my condition?
Surgical intervention for AVN is used to either deter or delay progression of early disease or to treat advanced disease. For early stage AVN, currently, the most commonly performed surgical intervention is known as core decompression. This procedure involves drilling into your hip bone and removing a core of dead bone.
While core decompression can produce good results, it frequently has only a temporary effect and AVN can reoccur. A new, minimally invasive procedure, called the bone marrow aspirate concentrate (BMAC) procedure, involves drilling into the dead bone and then using a sterile needle to take bone marrow stem cells from the anterior iliac crests (the front parts of the pelvic bone) and injecting the bone marrow stem cells into the dead bone in the hip. It is thought that this can provide a significant benefit in treatment of this condition by preventing further progression of the disease and by stimulating new bone growth. In the BMAC procedure, the incision at the hip is less than ¾ of an inch and is closed with two staples. The incision at the anterior iliac crest to obtain the bone marrow is about ¼ of an inch and is closed with dissolvable sutures.
What are the risks of the BMAC procedure?
As with any surgery, BMAC injections with bone marrow grafting have possible risks and complications. These include:
- Reaction to anesthesia
- Blood clots
- Damage to the nearby blood vessels, bones or nerves
- Pain at the site of bone marrow aspiration
- Hematoma at the site of BMAC
- Fracture of the hip
- Breakage of a surgical device in the bone
What is the recovery time for the BMAC procedure?
After the surgery, all patients receive antibiotics for twenty-four hours to lessen the risk of infection. If one hip is treated, patients typically do not stay overnight and are discharged the same day. Instructions and pain medication is provided. If both hips are treated a one-night stay is recommended. You will generally not have to go to a rehabilitation facility after the BMAC procedure. In most cases, you will be able to go directly home from the hospital.
How long after the BMAC procedure can I Walk?
You can put weight on the operated leg as long as you use a cane (for one hip) or crutches (If both hips are treated). We will teach you how to use canes and crutches before you go home from the hospital. This lasts for 6 weeks. After that you may walk normally but no athletic activites involving your legs are allowed. At six months you can engage in exertional physical activity as tolerated but you should avoid impact sports. To summarize, weight bearing status after BMAC injection procedure is as follows:
- Protected weight bearing (use of cane or crutches) first 6 weeks
- Full weight bearing without cane or crutches after 6 weeks
- Exertional physical activity at six months
When are the sutures removed?
Generally, sutures over the incisions are removed fourteen days (2 weeks) after the surgery.
How long will I be on pain medication?
It is not unusual to require some form of pain medication for several days after the BMAC procedure. Most patients are able to discontinue narcotic medication after a couple of days and switch over to an over-the- counter medication such as acetaminophen, ibuprofen or naproxen.
When can I shower or get the incision wet?
You may shower 3 days after your operation, if no drainage is present at the incision site.
When can I drive?
Once you receive permission to do so from your surgeon, you may generally resume driving after 3 weeks of having a BMAC procedure.
When can I return to Work?
It depends on your profession and how you feel. Typically, if your work is primarily sedentary, you may return to work after a BMAC procedure within a week or two if you feel well enough to do so. If your work is more rigorous, you may require more time before you return to work.
When can I travel?
You may travel as soon as you feel comfortable.
What activities are permitted following surgery?
If you have AVN of the hip you must adjust how you participate in sports after you have surgery. Even If this condition is successfully treated, impact sports are not allowed. You can maintain and achieve physical fitness with physical activities that are easy on your joints such as swimming, biking, brisk walking and using the elliptical trainer. You should avoid high-impact sports such as running and jumping, and vigorous sports such as singles tennis or squash.
Will I need physical therapy?
Generally, you will not need formal physical therapy following a BMAC procedure unless your surgeon determines that you need to strengthen the muscles around your hip.
When can I resume sexual activity?
There are no restrictions on resuming sexual activity after the BMAC procedure. You may resume sexual relations as soon as you feel well enough to do so.
When do I need to follow up with my surgeon?
Follow-up care involves evaluation at two weeks postoperatively to have the sutures or staples removed. This can be done by a local doctor near your home. X-rays at 6, 12, 18, and 24 months are generally required. An MRI is done preoperatively and at 24 months and 48 months postoperatively to determine if there is evidence of new bone growth.
What If I have advanced AVN of the hip?
For some patients with advanced AVN, a procedure called the trapdoor procedure can be useful to prevent having to undergo a total hip replacement. The procedure involves a six-inch incision, opening and dislocating the hip joint, called trapdoor in the articular cartilage. Bone grafting transplants are taken from healthy bone in the pelvis. Using the trapdoor procedure, dead bone is removed from the femoral head and replaced by bone grafts, which are used to stimulate new bone growth.
What happens if I choose not to get treated?
If AVN of the hip is untreated, this condition will eventually lead to decay of the bone and collapse (destruction) of the hip joint, which then requires hip replacement surgery. Collapse occurs in approximately 67% of patients with AVN of the hip who have no symptoms, and in more than 85% of those patients who do report symptoms.
Total Hip Replacement
Total hip replacement is the treatment of choice in advanced AVN when the hip joint is destroyed due to collapse and advanced osteoarthritis. In this procedure, the diseased hip joint is replaced with artificial parts made of metal and either plastic or ceramic. A prosthetic hip replacement generally lasts 15 years before it wears out and needs to be revised.