Medically Reviewed by Dr. K on 12 April 2021
Table of Contents:
- What Is Avascular Necrosis?
- Symptoms of Avascular Necrosis
- Causes and Risk Factors for Avascular Necrosis
- Who Gets Avascular Necrosis?
- Avascular Necrosis Diagnosis
- Avascular Necrosis Treatment
- Caring for Avascular Necrosis at Home
- Prognosis for Avascular Necrosis
Avascular Necrosis (Osteonecrosis)
What Is Avascular Necrosis?
The death of bone tissue due to a lack of blood flow is known as avascular necrosis (AVN). Osteonecrosis, aseptic necrosis, and ischemic bone necrosis are also terms used to describe this condition.
AVN may cause the bone to collapse if it isn't treated. The hip is the most frequent occurrence in AVN. The shoulder, knees, and ankles are also common locations.
Symptoms of Avascular Necrosis
AVN normally has no symptoms in the early stages. It becomes painful as the condition progresses. It can just hurt when you place pressure on the injured bone at first. Then the pain can become chronic. You can experience intense pain and be unable to use your joint if the bone and underlying joint collapse. The interval between the occurrence of symptoms and the beginning of bone collapse will vary anything between a few months to over a year.
Causes and Risk Factors for Avascular Necrosis
Several factors may increase the chances of avascular necrosis:
- Alcohol. Multiple drinks a day will result in fat deposits forming in your blood, reducing the blood supply to your bones.
- Bisphosphonates. These medications that increase bone density can result in jaw osteonecrosis. This is more likely if you are receiving treatment for multiple myeloma or metastatic breast cancer.
- Medical treatments. Radiation therapy for cancer can cause bone deterioration. Additional conditions associated with AVN include organ transplantation, especially kidney transplantation.
- Steroid drugs. Long-term use of these anti-inflammatory medications, either orally or by injection, contributes to 35% of all cases of nontraumatic AVN. Doctors are unsure why, but long-term use of drugs such as prednisone has been linked to AVN. They believe the medications will increase fat levels in the blood, thus decreasing blood flow.
- Trauma. When a hip is broken or dislocated, it can cause damage to surrounding blood vessels, cutting off the blood flow to your bones. AVN can affect 20% or more of individuals who dislocate a hip.
- Blood clots, inflammation, and damage to your arteries. All of these factors will lead to a reduction in blood flow to your bones.
Additional conditions associated with nontraumatic AVN include the following:
- Decompression sickness, which results in the formation of gas bubbles in your blood
- Gaucher disease, which is a condition whereby a fatty material accumulates in the organs
- Prolonged use of bisphosphonates to treat cancers such as multiple myeloma or breast cancer may result in AVN of the jaw.
- Pancreatitis, inflammation of the pancreas
- Radiation therapy or chemotherapy
- Autoimmune diseases such as lupus
- Sickle cell disease
Who Gets Avascular Necrosis?
Each year, up to 20,000 people develop AVN. The majority are between the ages of 20 and 50. The risk of contracting AVN is extremely low in healthy individuals. In most cases, an underlying health issue or accident was the cause.
Avascular Necrosis Diagnosis
Your doctor will begin with a physical examination. They'll apply pressure to the joints to see if there are any sore spots. They can adjust the joints in a set of positions to determine your range of motion. You can undergo one of the following imaging tests to determine the source of your pain:
- Bone scan. A radioactive substance is injected into the vein by the doctor. It travels to areas of injured or healing bones and appears in the scans.
- MRI and CT scan. These provide your doctor with accurate images of early bone changes that could be indicative of AVN.
- X-rays. They will be common in the early stages of AVN but can indicate bone changes later on.
Avascular Necrosis Treatment
The aims of treatment for AVN are to strengthen the joint, halt bone loss, and alleviate pain. The optimal form of treatment would depend on a variety of factors, including:
- Your age
- The disease's stage
- The site and extent of bone damage
- AVN's cause
If avascular necrosis is detected early, treatment can include pain relief or restriction of use of the affected region. If your hip, knee, or ankle is injured, you can use crutches to relieve pressure on the injured joint. Additionally, your doctor can prescribe range-of-motion exercises to assist in keeping the joint mobile.
- Medications. If your doctor is aware of the cause of your avascular necrosis, treatment will focus on managing it. This includes the following:
- Blood thinners. These are the symptoms you'll experience if your AVN is caused by blood clots.
- Nonsteroidal anti-inflammatory drugs (NSAIDs). These can alleviate pain.
- Cholesterol drugs. They lower cholesterol and fat levels in the blood, which can help avoid AVN-causing blockages.
- Surgery. Although nonsurgical treatments may help to delay the progression of avascular necrosis, the majority of people with the condition may ultimately need surgery. Surgical solutions include the following:
- Bone grafts. Remove and replace the weakened bone with healthy bone from one part of the body
- Osteotomy. Cut the bone and change its orientation to reduce bone or joint tension
- Total joint replacement. The damaged joint is removed and replaced with a synthetic joint.
- Core decompression. To relieve pressure and allow new blood vessels to develop, a portion of the inside of the bone is removed.
- Vascularized bone graft. Rebuilding diseased or weakened hip joints with your own tissue. The surgeon first removes the bone with insufficient blood supply from the hip and then replaces it with bone rich in blood vessels from another location, such as the fibula, the smaller bone in your lower leg.
- Electrical stimulation. An electrical current can be used to stimulate new bone development. Your doctor can use it during surgery or provide you with a special device for it.
Caring for Avascular Necrosis at Home
You can do these things to help:
- Rest. Stay off the joint.This will help to mitigate the effects of the injury. For some months, you can need to limit your physical activity or use crutches.
- Exercise. A physical therapist will teach you how to regain your joint's range of motion.
To reduce the chances of developing AVN,:
- Cut back on alcohol. Heavy drinking is one of the leading causes of AVN.
- Keep your cholesterol in check. The most common thing that blocks blood flow to your bones is small bits of fat.
- Use steroids carefully. When you're on these medications, the doctor should keep an eye on you. Let them know if in the past you used them. Taking them repeatedly will exacerbate bone damage.
- Don't smoke. It increases the chance of AVN.
Prognosis for Avascular Necrosis
About half of those diagnosed with this disorder need surgery within three years of diagnosis. If one of your bones collapses in one of your joints, it is more likely to break in another.
Your perspective is contingent upon a number of factors:
- The stage of disease when the first time you were diagnosed
- Whether you have an underlying health problem
- You’re less probably to do well if:
- You're over the age of 50.
- When you are diagnosed, you are in stage III or higher.
- More than a third of the weight-bearing region of the bone is dead.
- The harm extends beyond the end of the bone.
- You've had a long history of cortisone treatments.