Ask the Expert: Avascular Necrosis

by Dr. Charles Cornell
2.26 Blog

In this week’s edition of Ask the Expert, Dr. Charles Cornell, Orthopedic Surgeon, answers questions in relation to avascular necrosis.

Q1. What is avascular necrosis?

Avascular necrosis (AVN) is a disorder of bone that results from vascular injury. Bone is nourished by microscopic blood vessels that do not have cross circulation. In the femoral head, or ball of the hip joint, small microscopic parallel vessels provide blood supply to the bone of the femoral head. If those vessels become clogged, the area of bone supplied by that vessel dies. It appears that large circulating fat complexes or blood clots are most likely responsible for creating these clogs. Generally, many of the vessels become clogged at the same time causing a large infarct of the femoral head bone. Once the bone dies, the body responds by removing the dead bone and replacing it with new living bone. This is a slow process that occurs over many months. The disorder resulting from AVN is caused by the fact that the dead bone is resorbed faster than the new bone is formed so the structure of the bone is weakened. The weakening can be so extensive that the bone of the femoral head cannot carry normal weight bearing loads and fractures leading to collapse of the structure of the normally round femoral head. When this occurs, the perfect fit between the ball and socket of the hip is lost leading to arthritis. The collapse itself can also be painful. When collapse occurs, hip replacement is usually needed.

Q2. What are some of the causes of avascular necrosis?

Avascular necrosis of the femoral head (AVN) is associated with use of certain drugs and with certain diseases. Alcoholism and prolonged use of steroid medications can lead to AVN. Sickle cell anemia causes avascular necrosis and hip disease is a common morbidity associated with this blood disease. Rheumatologic diseases, most notably systemic lupus erythematous and the immune vascular diseases, are frequently associated with the development of AVN. HIV infection and AIDS is currently one of the most commonly associated diseases with this disorder. Finally, patients who recipients of organ transplants frequently develop AVN which may be associated with the transplant itself as well as the anti-rejection medications that are required. In my own experience, many patients present with no obvious risk factor for development of the disorder. I refer to these cases as “idiopathic AVN”. In these cases, it is important to rule out other diagnoses that can present similarly. These include insufficiency fractures and transient osteoporosis. These disorders are similar but usually result from calcium and vitamin D deficiency or some other metabolically caused bone weakness. Whenever I suspect AVN, I have the patient undergo a thorough diagnostic work-up to detect any deficiency or other cause of bone weakness.

Q3. What should you do if you are diagnosed with avascular necrosis?

If you are diagnosed with AVN, seek out treatment from a specialist interested in the disease. Endocrinologists, rheumatologists and orthopedic surgeons are the subspecialties that usually treat this disorder. Treatment remains very controversial and traditional surgical procedures such as core decompression have been prescribed. In my view, there is almost no scientific support for surgical treatment of the early stages of this disorder. From our understanding of the pathologic process, core decompression and vascularized grafting procedures make little sense and published clinical reports provide little evidence of consistent success. We have had excellent and consistent success treating our patients with bisphosphonate drugs which inhibit bone resorption. These drugs are also used to treat osteoporosis. These agents inhibit the bone resorbing cells called osteoclasts but allow the bone forming cells, osteoblasts, to continue the process of new bone formation unopposed. We believe this treatment is successful because it stops the bone resorption that weakens the bone yet allows repair to continue unopposed. Patients should seek out specialists familiar with this approach.

Q4. What happens if you do not diagnose avascular necrosis early?

Unfortunately, AVN is relatively asymptomatic in the early stages. Pain in the affected hip often does not present until the bone structure is weakened and collapse has begun. As a result, many patients don’t present until the hip is already damaged. If you are diagnosed with AVN, treatment from a specialist should be sought immediately. If you are diagnosed with AVN in the early stages, AVN can be successfully treated with a bisphosphonate drug.

Q5. Is there any current research available for avascular necrosis?

There is a lot of research being performed to improve the treatment of AVN. Most research concerns better drug treatment. There are new antiresorptive drugs being developed as well as drugs which stimulate the bone forming cells. It would make sense that applying a drug that stimulates the ingrowth of new bone would add to the effect of slowing bone resoprtion in preserving the intact bone structure before collapse occurs. Modifications of surgical procedures are also being developed in which stem cell implants are placed into the necrotic area to speed repair. I see this as a promising method to address the intermediate stages where some damage to the structure of the femoral head has occurred but before the collapse is bad enough to result in hip arthritis requiring hip replacement. Finally, research is also being performed to assess the outcome of total hip replacement when it is needed. In the 1980’s when hip replacements were usually implanted with cement, the long term durability of the artificial hips was noted to be poor. However, modern implants seem to perform well for AVN and current research is being done to verify this.

Dr. Charles N. Cornell is a Joint Replacement Surgeon and Clinical Director of Orthopedic Surgery at Hospital for Special Surgery. Dr. Cornell is board certified by the American Board of Orthopedic Surgeons and was admitted as a Fellow to the American Academy of Orthopedic Surgeons as well as the American College of Surgeons. Dr. Cornell’s areas of expertise include avascular necrosis, fractures and trauma, and total joint replacement, care of arthritis and geriatric orthopedics.

Topics: Ask the Expert, Featured, Orthopedics
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The information provided in this blog by HSS and our affiliated physicians is for general informational and educational purposes, and should not be considered medical advice for any individual problem you may have. This information is not a substitute for the professional judgment of a qualified health care provider who is familiar with the unique facts about your condition and medical history. You should always consult your health care provider prior to starting any new treatment, or terminating or changing any ongoing treatment. Every post on this blog is the opinion of the author and may not reflect the official position of HSS. Please contact us if we can be helpful in answering any questions or to arrange for a visit or consult.

Comments

mike soto says:

i have AVN in the early stage but i have severe hip pain…I also have enlarged lymph nodes on the left groin and pelvic sidewall…not sure what to do.?

HSS on the Move says:

Hi Mike, thank you for reaching out. Dr. Charles Cornell, Orthopedic Surgeon, says: “Early AVN can be treated with bisphosphonates. They can help with the pain. I don’t think the lymph nodes are related if the hip issue is really AVN.” It is best to consult with your treating physician. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

Thomas Hopkins says:

Dr Cornell, I have a vascular necrosis of my shoulders. It is pre-collapse of the humeral head. Is surgery my only alternative. Or can treatment with a frog like reclast make a difference? Is treatment the same for the shoulders as the hips? Thank you.

HSS on the Move says:

Hi Thomas, thank you for reaching out. Dr. Charles Cornell, Orthopedic Surgeon, says: “Collapse of the humeral head is rare, but pain can be an issue. The pain does respond to biphosphonate therapy and I would agree that Reclast infusion would be indicated.” It is best to consult with your treating physician. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

HSS on the Move says:

Hi Thomas, thank you for reaching out. Dr. Charles Cornell, Orthopedic Surgeon, says: “Collapse of the humeral head is rare, but pain can be an issue. The pain does respond to biphosphonate therapy and I would agree that Reclast infusion would be indicated.” It is best to consult with your treating physician. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

Carol says:

Hi Dr. Cornell, I was diagnosed with avascular necrosis of my right hip which was caused by a short term/high dose steroid prescription. A total hip replacement was done 1 1/2 years ago with an uncemented stem. After reading your article, I was wondering if there is anything I should be watching out for. I was also wondering if AVN is completely resolved with replacement of the affected joint.
Thank you in advance for your response.

HSS on the Move says:

Hi Carol, thank you for reaching out. Dr. Charles Cornell, Orthopedic Surgeon, says: “The AVN is resolved with the hip replacement. All should be well. Be sure to supplement calcium and vitamin D3. Talk with your primary MD about an appropriate supplement.” It is best to consult with your treating physician. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

HSS on the Move says:

Hi Carol, thank you for reaching out. Dr. Charles Cornell, Orthopedic Surgeon, says: “The AVN is resolved with the hip replacement. All should be well. Be sure to supplement calcium and vitamin D3. Talk with your primary MD about an appropriate supplement.” It is best to consult with your treating physician. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

Felipe Costa says:

Dear Dr. Cornell
I have an aneurysmal bone cyst in my calcaneus and an AVN of the talus. The cyst has appeared before the AVN of talus. Do you think is probably that the AVN of talus would be associated with the ABC of calcaneus?
Thanks

HSS on the Move says:

Hi Felipe, thank you for reaching out. For more information on avascular necrosis, please visit http://www.hss.edu/condition-list_avn-avascular-necrosis.asp. It is best to consult with your treating physician so they can better advise. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

AHM Rezaul Karim says:

Dear Sir, I am from Bangladesh would like to know that my younger brother (30 years) has been suffering from AVN (left hip) for 2 years. On 2012 core decompression was done but no successful result is obtained. As a result he has been suffering from pain and other difficulties. Now the doctors of Bangladesh suggest to go for hip replacement. But considering his age, is there any medical treatment exists without hip replacement. I would be highly grateful if you kindly inform me. If you give me your email address, then i would send the soft copy of medical reports.

HSS on the Move says:

Hello, thank you for reaching out. Dr. Charles Cornell, Orthopedic Surgeon, says: “If the core decompression failed, the best treatment is likely total hip replacement. If the head has collapsed, there is no alternative. If the architecture of the hip is still relatively normal, a trial of biphosphonates and Vitamin D should be attempted.” It is best for your brother to consult with his treating physician so they can better advise. If your brother wishes to receive care at HSS, please contact our International Center at 212-606-1186 or by email at international@hss.edu.

Maryann Kriegsman says:

I had bilateral total knee replacement 3 years ago. I did fall on both knees 4 times. The discomfort has gotten progressively worse. I now have pain in both knees with severe pain on steps. I have been diagnosed with AVN. The surgeon has suggested a bi-lateral release of the patella but said the chance of success is only 60%. The surgeon has said that I may have to learn to live with the pain.I also have gone through several sessions of physical therapy without success. Do you have any suggestions or do you know of any doctors in central New Jersey that specialize in AVN, Thank you.

HSS on the Move says:

Hi Maryann, thanks for reaching out. It is best for you to consult with your treating physician who is most familiar with your medical history and course of treatment. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance. For more information, visit http://www.hss.edu/physician-referral-service.

sherry says:

My husband has just been diagnosed with early stage AVN in his right hip. They have prescribed surgery by coring out the bone and inserting cement. After reading this, am I understanding that this is not a good option with the cement? He is in his 50′s.

HSS on the Move says:

Hi Sherry, thank you for reaching out. Dr. Charles Cornell, Orthopedic Surgeon, says: “It has been our experience that core decompression is not necessary and is not particularly effective. We have had better success with drug treatment avoiding the surgical procedure. Additionally, at 50 years of age we would perform a work-up to be sure AVN is the correct diagnosis.” It is best that your husband consults with his treating physician. If he wishes to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

Ellen Bambrick says:

My son who is 30 years old has been recently diagnosed with AVN Stage 4 in both hips. Underlying cause is still unkown. Is hip replacement the only alternative.

HSS on the Move says:

Hi Ellen, thank you for reaching out. Dr. Charles Cornell, Orthopedic Surgeon, says: “Although AVN occurs commonly in young males, there is usually an identifiable cause. If the hip involvement is indeed stage IV, then hip replacement is the best treatment. However, I would try a course of medical therapy first to see if the pain can be reduced. This can often delay the need for hip replacement for several years. Please be sure your son has had a metabolic bone evaluation by a specialist before he has surgery.” It is best for your son to seek an in-person consultation with a treating physician. If he wishes to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

RITESH AGARWAL says:

Dear Sir
I m diagnosed with AVN OF HIP ONE MONTH BACK. AS PER DOC IT IS STAGE 2 IN LEFT AND 1 IN RIGHT. I HAVE STARTED BISOPHANATE DRUG AS ADVISED. PLS ADVISE IF THIS IS THE RIGHT TREATMENT FOR AVN.PLS HELP

HSS on the Move says:

Hi Ritesh, thanks for reaching out. For more information on AVN, click here: http://www.hss.edu/condition-list_avn-avascular-necrosis.asp. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

suresh says:

I was diagnosed with avn 10 years ago. I”m still working , go fishing etc ,is this normal. What was the longest 1 had to wait before surgery

HSS on the Move says:

Hi Suresh, thanks for reaching out. For more information on AVN, click here: http://www.hss.edu/condition-list_avn-avascular-necrosis.asp. If you wish to receive care at HSS, please contact our Physician Referral Service at 877-606-1555 for further assistance.

Pawan Mittal says:

My 22 year old son suffering from Myelopathy(suspected and undignosed Granulmatous/Sarcoidosis/Tuberuculosis) was given Prednisolone 40Mg for 21 days,35 Mg for 10 days,25 Mg for 15 days,20 Mg for 10 days,and continuing on tapered dose,develped AVN in right Hip termed as Stage 2nd) and being treated under Dr Sanjay Agrawala of Hinduja Hospital,Mumbai.He was administered Injection Aclasta and being administered 70 Mg of Alendronic acid weekly with Calcium and Vitamin E intake for past 18 days.He is on crutches and still not feeling better as far as pain in right hip is concerned.I shall be thankful if you can please inform that his treatment is on right course or any other treatment is more preferable.

HSS on the Move says:

Hi Pawan, we appreciate you reaching out to us. However, we think it would be best for your son to consult with his treating physician or seek an in-person consultation for a second opinion. If he is interested in receiving care at HSS, please contact our International Center at 212-606-1185 or by email at international@hss.edu for further assistance. For more information on the International Center at HSS, please visit http://www.hss.edu/international-center.asp.

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