Avascular Necrosis FAQ’s
What is avascular necrosis and what causes it?
Avascular necrosis, also called osteonecrosis is a condition in which bone death occurs because of inadequate blood supply to it. Lack of blood flow may occur when there is a fracture in the bone or a joint dislocation that may damage nearby blood vessels.
AVN is caused from insufficient blood supply to the bone. There are several causes of avascular necrosis. However no specific cause is found. The common causes of avascular necrosis include:
- Trauma: Dislocation or bone fractures can injure blood vessels
- Long term or high dose steroid treatments
What is avascular necrosis of the hip?
Avascular necrosis of the femoral head (AVN) is a debilitating condition that leads to destruction of the hip joint in young patients. The average age of patients who suffer from avascular necrosis of the femoral head is significantly younger than patients who suffer from arthritis due to degenerative conditions.
Can avascular necrosis spread from the hip to other parts of the body?
Avascular necrosis cannot spread from one body part to the other. However, there are certain conditions, which cause avascular necrosis in numerous joints of the body. Avascular necrosis may affect numerous bones in certain disorders.
However, if a patient has avascular necrosis in a certain bone or a certain joint, the avascular necrosis by itself does not spread to other parts. There are certain conditions, which are certainly localized, as an example; trauma to the hip, which causes avascular necrosis of the hip and the patients should expect that in such a scenario, in the absence of other conditions the avascular necrosis is going to stay in the same body part.
What are the conditions associated with avascular necrosis?
I classify conditions as acute onset and chronic onset conditions. Some common causes of chronic onset avascular necrosis include use of corticosteroids as an example for treatment of systemic lupus erythematosus, rheumatoid arthritis, or in patients with renal transplantation or asthma. The use of alcohol also is associated with avascular necrosis of the femoral head. Sickle cell anemia and other anemias can also cause avascular necrosis of the femoral head.
There are certain less common conditions, like Gaucher’s disease, myeloproliferative disorders, some coagulation deficiencies that can give rise to avascular necrosis. Caisson’s disease, chronic pancreatitis, and radiation can also cut off the blood supply to the femoral head and can cause avascular necrosis.
The acute conditions that can cause avascular necrosis of femoral head are dislocation of the femoral head and fracture of the neck of the femur.
Approximately what percentage of avascular necrosis have no identifiable cause?
A majority of patients in my practice who present with avascular necrosis do not have an identifiable cause.
What causes Avascular Necrosis?
There are multiple theories about the pathogenesis of avascular necrosis of the femoral head, which in acute reduction in the blood supply to the bone resulting from circulating fat, nitrogen bubbles or abnormally shaped cells, increased bone matter pressure, arterial obstruction, obstruction to the venous outflow, injury to the wall of the vessel caused by vasculitis, radiation damage, or release of inflammatory factors. I feel that most of avascular necrosis are multifactorial.
What are the symptoms of avascular necrosis?
Avascular necrosis, in the earlier stage, is asymptomatic. This is the stage where we would like to catch the disease and treat it with core decompression and stem cells so that the possibility of arthritis and the need for joint replacement surgery is avoided. In the early stages of avascular necrosis, the patient complain of groin pain and as the collapse increases, there is increasing joint pain.
How is Avascular Necrosis classified for treatment purposes?
I classify avascular necrosis based on the degree of damage to the femoral head. I classify them according to severity from Stage 0 to Stage IV.
In Stage 0, the patient has no symptoms. The x-rays are normal. The bone scan may show decreased uptake.
In Stage I, there are no symptoms, the x-ray’s normal, the bone scan shows a cold spot, and if you do a biopsy it shows infarction of the weight-bearing portion of the femoral head. Bone biopsy will show abundant dead matrix cells, and osteoblast, and osteogenic cells.
In Stage II the patient has mild systems. On X-ray there is a density change in the femoral head like sclerosis or cysts. In Stage IIA and IIB, the Xray appearance of the femoral head is characterized by flattening. We call it the “Crescent sign”. The bone scan shows increased uptake in Stage II and a biopsy shows new bone deposited between necrotic layer of the bone.
In Stage III, the symptoms are mild to moderate. The x-rays show loss of sphericity and collapse. Bone scan shows increased uptake, and the pathogenic findings on the biopsy consist of a subchondral fracture and dead bone cells.
Stage IV is the most serious form of avascular necrosis. The patient has significant symptoms. There is joint space narrowing. There are acetabular changes, which means there are changes on both sides of the joint. Bone scan shows increased uptake and there are significant osteoarthritic changes on both sides of the joint.
Why is avascular necrosis also called Bo Jackson’s Disease?
As we know that Bo Jackson was a baseball and football player and sustained an injury in 1991, which ended his career. I watched the video of the injury and although there’s a feeling that Bo Jackson dislocated his hip, it’s more likely that he injured his hip or fractured his hip.
This injury probably cut off the blood supply to the head of the femur leading to avascular fitness. It’s unlikely for a native hip to be relocated without anesthesia.
A native hip is a very stable joint and if dislocated it needs anesthesia, and a surgical maneuver to relocate the hip. I therefore feel that in the case of Bo Jackson, it was a break in his bone that cut off the blood supply that led to avascular necrosis and a subsequent end to his career.
What are the other names for avascular necrosis?
The other names for avascular necrosis are osteonecrosis, aseptic necrosis, or ischemic necrosis, all of which mean a condition where there is loss of blood supply to the bone.
How is AVN diagnosed?
The aim of any treatment is to minimize the disability and minimize the pain caused from avascular necrosis. I start with diagnostic evaluation, which starts with an x-ray. In cases with a very high clinical suspicion, I do a bone scan or an MRI. As discussed, the bone scan may show a cold spot in Stage 0 of avascular necrosis and the x-rays are essentially normal. The MRI is more useful in the earlier stages of the disease.
Can homeopathy cure avascular necrosis?
I am not aware of any homeopathic medication that can cure avascular necrosis. If you wish to consider alternative therapies, it’s best to contact the provider directly. I cannot opine on non-approved therapies for treatment of avascular necrosis.
How do I deal with the pain from avascular necrosis?
You can try over-the-counter medications. However, most types of avascular necrosis are progressive and will give rise to progressive pain and disability if not treated.
How do I treat avascular necrosis naturally?
I am not aware of any natural therapies for the treatment of avascular necrosis.
How do steroids cause avascular necrosis?
Steroids interfere with the circulation to the head of the femur, which is susceptible to die, and therefore the steroids cause avascular necrosis, especially of the hips.
Is AVN treated completely by hip replacement surgery?
During hip replacement surgery the head of the femur is removed, along with the socket. The entire part of the bone that has become necrotic due to lack of blood supply is removed, and therefore total hip replacement is the final cure for avascular necrosis.
Can you die from avascular necrosis?
Patient mortality is not possible from avascular necrosis of the hip alone. Most of the conditions that cause avascular necrosis of the hip affect the patient’s regional body parts and are not considered risk factors by themselves for mortality. The risks of the surgery for avascular necrosis can be associated with mortality, and that risk has to be discussed preoperatively with the surgeon.
Can AVN continue to happen in an already replaced joint replacement?
No, obviously avascular necrosis cannot happen in a joint replacement because the part of the bone that is necrosed is removed and is replaced with a prosthetic device. It is however possible to have avascular necrosis adjacent to the joint replacement surgery. And if the patient has continuous symptoms, this should be investigated by the surgeon.
What can you do to prevent avascular necrosis?
Avascular necrosis can be prevented by decreasing the risk factors that cause avascular necrosis in the first place. As an example, patients who are alcoholics can decrease their alcohol or eliminate the intake of alcohol. Sickle cell anemia needs to be controlled. The use of corticosteroids for treatment of asthma or systemic lupus erythematosus should be minimized.
In a patient of trauma, as the example with hip dislocation, the dislocation should be reduced immediately and if the patient has suffered from the fractured neck of the femur, the fracture has to be reduced in a minimally invasive manner and fixation has to be accurate. This can prevent or delay the onset of avascular necrosis.
For younger patients with avascular necrosis of the femur, would you still recommend a hip replacement?
Total joint replacement surgery remains the last choice for patients with avascular necrosis. Total joint replacement surgery is done only when there is significant arthritis and the sphericity of the head of the femur is lost because of lack of blood supply.
Today it is not acceptable for younger patients to remain in pain, and disabled, and have no mobility because of the pain from avascular necrosis. I have done several surgeries in younger patients because there was no choice for them apart from suffering in pain and being on pain medications.
How close is life after the surgery in younger patients after the joint replacement surgery done for avascular necrosis?
Younger patients do extremely well after joint replacement surgery done for avascular necrosis. They are completely pain-free and continue to live productive lives pain-free.
Is stem cell treatment effective to cure avascular necrosis of the hip?
It depends on the stage of the disease. I use core compression and stem cell therapy in the early stages of the disease. For advanced stages of the disease, the French have used it and have shown improvement, however, I feel that for patients who have significant arthritis from avascular necrosis are best benefited by joint replacement surgery.
What are the recommendations for routine workout for someone who is young with avascular necrosis of the femur?
I would suggest non-impact type of activities for patients with avascular necrosis. Any impact type of activity is going to aggravate the collapse, the pain, and increase the risk of arthritis in the hip joint.
Is avascular necrosis painful?
Avascular necrosis is painful in the later stage of the disease. In Stage 0, the x-ray is not affected. Avascular necrosis is only seen on a bone scan and on the MRI. And this is the time when I advise intervention even without symptoms. This is among the rare situations where patients get surgery without symptoms. The idea is to decrease the risk of joint replacement surgery in the future.
Can avascular necrosis heal on its own?
There are certain types of avascular necrosis which heal on their own. These are rare and the patient should discuss the findings with the surgeon to see if that is a possibility. Serial MRIs or serial bone scans can be done in these cases to monitor the avascular necrosis and to ensure it is not progressing.
How Fast Does Avascular Necrosis Progress?
The progression of avascular necrosis depends on numerous factors including the cause of avascular necrosis in that particular patient. Additionally, I would also consider the time from which the diagnosis has been made to the time of presentation of pain as an additional factor.
For example, if the avascular necrosis has been diagnosed on MRI a year ago, and the patient is still not symptomatic, it would suggest that the progression is significantly slow. The patient should understand that the onset of MRI typically precedes the onset of pain of avascular necrosis.
Under certain circumstances, I would consider a repeat MRI to see if there is any progression or regression of the disease. I would also consider a comparison of the new MRI with the MRI done before to see if the disease has progressed or regressed since the time of the first MRI.
What is the difference between avascular necrosis and osteonecrosis?
Both avascular necrosis, osteonecrosis, ischemic bone necrosis, aseptic necrosis mean the same.
Can you heal from necrosis?
It depends on the cause of necrosis, where it is located, and the size of the necrotic lesion, whether the necrotic lesion is associated with arthritis, and the treatment taken for the necrosis.
Is avascular necrosis genetic?
I believe there is a genetic component for avascular necrosis which makes a particular patient more susceptible for a stimulus than others.
Can AVN be treated conservatively?
In my opinion, protected weight-bearing has not shown to improve the course of the disease. Eventually the patients develop pain and it is not a good, long-term option. There are certain pharmacological agents available, like Alendronate and Fosamax, which have not shown to give good long-term relief. Electrical stimulation has also been tried, but the results are not really satisfactory.
How is early AVN treated?
In the early stages of the disease, I do core decompression, which means I use small drill holes to core in and remove the diseased part of the bone. This has been shown to improve the blood supply to the femoral head. In addition, I like to use stem cells to augment the procedure and improve the possibility of the bone healing.
My preferred method for using stem cells is by aspirating the iliac crest, which means the pelvis of the patient, taking out the hematopoietic blood cells, spinning them around, concentrating them, and then injecting it into the core decompression space. This has shown excellent results and the pain from the avascular necrosis is alleviated in the early stages of avascular necrosis.
If the patient has significant collapse and significant arthritis, the only option available is a joint replacement surgery. Osteotomy ( surgical rotation of the part of the bone which is diseased ) has been described by Japanese investigators, including Sugioka, but the results have not found to be satisfactory.
Vascularized as well as non-vascularized bone grafting has been used for avascular necrosis. But again, in my opinion, it has not proved to have satisfactory, predictable results.
To summarize, in the early stages of the disease I use core decompression with stem cells, and in the later stage of the disease I use joint replacement surgery to alleviate the pain and suffering from avascular necrosis.
Who is at a risk for avascular necrosis?
There are numerous predisposing factors for avascular necrosis. I classified them as one-time factors and chronic factors. One-time factors are fracture of the neck of the femur, and a dislocation of the hip joint. Chronic factors include use of corticosteroids, the use of alcohol, sickle cell disease, myeloproliferative disorders, coagulation deficiencies, and radiation.
Is AVN a progressive disease?
Avascular necrosis of the hip usually starts with a small area where the blood supply to the bone is cut off and it is usually in the weight-bearing part of the hip joint. As the disease advances, the head of the upper end of the thigh bone (femur) begins to collapse, there is formation of cysts, and eventually there is arthritis.
What is free vascularized fibular grafting to the hip joint?
Investigators have tried to use a free vascularized fibular graft to the hip joint to alleviate the pain of avascular necrosis. The fibula is the bone on the outside of the leg bone. Investigators have tried to take the blood supply, along with a piece of this bone, and then implant it into the hip joint, with the hope that the whole hip will vascularize and the collapse will be prevented. In my opinion, free vascularized grafting to the hip joint has not provided consistent results, and it’s a major procedure. I therefore do not use this for treatment of avascular necrosis of the hip.
Which AVN patients are candidates for surgery?
Any patient with early AVN but a high future risk of progression to advanced arthritis of the hip should have a core decompression along with stem cell implantation. Patients who have already developed significant arthritis need total hip replacement surgery.
There are a few cases in which I do core decompression to prevent further damage to the hip joint, even though the patient may not have pain. This is in patients where I see a lesion in the MRI and on bone scan, and I know that they are going to have avascular necrosis and problems in the future.
How is the surgery done?
In core decompression surgery, the patient is anesthetized and small drill holes are made from the outside of the hip that go inside the head of the femur. The diseased bone is cored out. This is done under X-ray guidance. It’s a small procedure and after injecting the stem cells into the upper end of the femur, the wound is closed. The patient can weight bear as tolerated after the surgery, and usually goes home the same day.
What are the advantages and disadvantages of free vascularized fibular graft?
A lot has been talked about free vascular fibular graft, but in my opinion, the results are not satisfactory and the disadvantages outweigh the advantages for this procedure. Thorough investigations have shown that the hip replacement surgery is delayed for a few years.
However, I am significantly worried at what cost. I have known patients who have had free fibular vascular graft who have been non-weight-bearing who have continued to have pain, and ultimately several years later they needed the joint replacement surgery. After a free vascular grafting to the hip joint, the results are unpredictable and the blood supply to that vascularized segment can get cut off again. The patient is on blood thinners, and I am not happy with the quality of life it offers. I therefore do not recommend this procedure.
What happens to the lower leg after the fibula is removed?
The fibula is removed in free vascularized grafting, and fibula is a non-weight-bearing bone. There is absolutely no change in the way the patient is able to walk. The patient is able to walk normally after a few weeks after the fibula bone is removed.
How long can I wait to make a decision to have surgery?
The surgery of core decompression or total joint replacement surgery is never done in a rush. We do a thorough preoperative evaluation. I always try to get to the cause of avascular necrosis, and try to treat the cause. Preoperative evaluation has to be done to ensure that it is safe for the patient to undergo surgery, and it is always done as elective surgery, never as emergency.
It’s okay to wait several weeks after being diagnosed with avascular necrosis, however, waiting too long will cause increased collapse of the bone and significant arthritis that will need joint replacement surgery. The idea of core decompression is to delay the onset of significant arthritis and delay the need for joint replacement surgery.
What kind of therapy will be needed following surgery?
After core decompression surgery, the patient can walk weight-bearing as tolerated with crutches. The crutches are used for a few days until the patient feels stable enough to walk without crutches. After joint replacement surgery, the patient walks with a walker the same day of surgery, and then with a cane in the contralateral upper extremity until the muscles are rehabilitated.
Will any medication be necessary after the surgery?
After both types of surgeries, core decompression and total joint replacement surgery, I use Aspirin for prevention of blood clots. It also helps in pain control and prevention of cardiac adverse effects after the surgery.
Will I need a blood transfusion?
After core decompression, a blood transfusion is not needed. After joint replacement surgery, the patient may need a blood transfusion depending upon what the blood values are prior to the surgery and also depending on how much blood loss has happened during the surgery. We use numerous techniques to decrease the blood loss including, tranexamic acid, which has shown to decrease blood loss during joint replacement surgery.
When will I be admitted to the hospital?
Most patients are required to the hospital a couple of hours before the actual surgery, and the hospital informs them of the exact time to come to the hospital.
What should I bring to the hospital?
The hospital will inform the patient what needs to be brought to the hospital. It usually includes a change of clothing. And any jewelry, or wallets, and purses are kept in security at the hospital and returned to the patient after the patient is ready to leave the hospital.
Will I have to bring anything special at home?
After core decompression surgery, usually the hospital will give crutches and the patient continues to walk weight-bearing as tolerated after the surgery. A high toilet seat, a walker, a nurse, and a physical therapist are set up for the patient before the patient goes home.
How long will I be out of work?
The patient’s absence from work depends on the type of surgery that was done and the type of work that the patient does. After core decompression, usually the patient leaves the hospital the same day. The patient can go back to low-load physical activity, like a desk job, after a couple of days. For heavy manual labor, after a core decompression, patients can return to work in about six weeks’ time.
After joint replacement surgery, I’ve known patients to go back to work within the week. However, for manual labor, I tell them to have a reasonable expectation of two to three months before they return to work.
What if I don’t want to get surgery?
Pharmaceutical agents, electrical stimulation has been tried with unsatisfactory results. If a patient with avascular necrosis declines surgery, there is likely to be progression in the disease of the avascular necrosis. The patient should consider surgical intervention if the patient needs pain medication on a daily basis.
I do not have any pain, my MRI shows avascular necrosis, do I need to be treated?
I understand it’s a tough decision to consider any sort of intervention in the absence of pain. However, it is only in the early stages of the disease that the patient has no pain, and this is exactly the time to consider treatment to prevent the progression of the disease.
I start by ensuring that it is really avascular necrosis on MRI and not similar looking condition on MRI. I then evaluate the causes of avascular necrosis in that patient and especially if I feel avascular necrosis is a cause that is likely to cause progression of avascular necrosis surgical treatment is indicated.
The patient has no pain in early stages of avascular necrosis according to all classification systems. Avascular necrosis manifests only on MRI in the earlies stage and it is not seen on an x-ray. If the patient has had progressive avascular necrosis in one hip, and if MRI shows avascular necrosis in the other hip I would consider surgical intervention early on to decrease deterioration of the affected hip, which shows only the MRI even if the patient does not have any pain.
The reason is to decrease the possibility of developing arthritis in the hip, especially if the other hip has had progression that has necessitated surgical intervention like a total hip replacement.
What classification system do you use for avascular necrosis of the hip?
What are the symptoms, X-ray findings, and bone scan findings in stage 0 of avascular necrosis?
What are the symptoms, X-ray findings, and bone scan findings in stage 1 of avascular necrosis?
What are the symptoms, X-ray findings, and bone scan findings of stage 2 of avascular necrosis of the femoral head?
What are the symptoms, X-ray findings, bone scan findings of stage 3 of avascular necrosis?
What are the symptoms, X-ray findings, and bone scan in stage 4 of avascular necrosis?
How do we differentiate between transient osteonecrosis of the hip (TOOTH) from avascular necrosis of the hip (AVN)?
Transient osteonecrosis of the hip is a self-limiting (as a term implies) condition that resolves with time. Transient osteonecrosis of the hip was initially described in the third trimester of pregnancy, however, it can also be found in other demographics including in young men.
The treatment of transient osteoporosis of the hip is conservative with protected weightbearing and close observation. MRI can differentiate between transient osteoporosis of the hip and osteonecrosis of the hip. MRI shows clear absence of a focal lesion. In transient osteoporosis of the hip, there is just diffuse edema on MRI. In osteonecrosis of the hip, subchondral collapse and focal abnormalities are very clearly seen.
It is important to distinguish between these two conditions because of transient osteonecrosis of the hip resolves over time while osteonecrosis typically is progressive and results in significant symptoms.
What fractures cause avascular necrosis of the hip?
Why does avascular necrosis hurt?
What is the most useful test to diagnose avascular necrosis of the hip?
Can I have a phone consultation with the doctor?
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