Hip Avascular Necrosis – Preservation & Replacement

Hip osteonecrosis, also known as avascular necrosis of the hip, is a condition caused by a decrease in blood flow to the femoral head as a result of a number of risk factors including trauma, sickle cell disease, steroid usage, alcoholism, autoimmune diseases, and hypercoagulable conditions.

Plain radiographs can be used to diagnose moderate/late conditions, but an MRI may be needed to detect early or subclinical osteonecrosis.

Avascular Necrosis treatment is mainly observation with the care of the underlying systemic disease. Advanced condition with subchondral collapse, femoral head flattening, and/or degenerative joint disease requires surgical therapy.

What is Avascular Necrosis?

Avascular necrosis occurs when the blood supply to your bone tissue is blocked up. Your bones are continually changing as your skeletal system produces new bone tissue to replace ageing bone tissue that breaks down and dies over time.

To replace the tissue that is breaking down and dying, your body creates new tissues. To keep your bones healthy and robust, this pattern must occur appropriately. The nutrients and oxygen that bones require to keep healthy and regenerate are carried by the blood. Your skeletal system can’t build new bone tissue fast enough if there is not an adequate blood supply. Results, the crumbling and eventual collapse of the decaying bone.

The blood flow to the head of the femur (thighbone) is disturbed, resulting in osteonecrosis of the hip, a painful disorder. Osteonecrosis can lead to the loss of the hip joint and severe arthritis because bone cells require a constant supply of blood to stay healthy.

Hip Avascular necrosis (HAVN) or aseptic necrosis are other names for osteonecrosis. Although osteonecrosis can affect any bone, it most commonly affects the hip. Every year, more than 20,000 people seek treatment for osteonecrosis of the hip in hospitals. Both hips are frequently damaged by the condition.

What Are the Symptoms of Avascular Necrosis?

The most prevalent signs and symptoms of avascular necrosis are listed below. Symptoms, on the other hand, can vary from person to person. Among the signs and symptoms are:

1. Minimal early joint pain
2. As the bone and joint begin to fail, there is an increase in joint pain
3. Due to pain, you have a limited range of motion

In the early stages of avascular necrosis, many persons experience no symptoms. Your damaged joint may only hurt when you put weight on it as the problem worsens. You might eventually feel discomfort even when you are lying down.

Pain can range from mild to severe, and it normally builds over time. Avascular necrosis of the hip can cause pain in the groyne, thigh, or buttock area. The shoulder, knee, hand, and foot, in addition to the hip, are likely to be affected.

Hip Avascular Necrosis can occur on both sides of the body (bilaterally), for example, in both hips or knees.

Avascular necrosis symptoms can resemble of other diseases or bone disorders. If you need a diagnosis, always consult with your doctor.

What Are The Causes of Hip Avascular Necrosis?

Avascular necrosis is caused by bone fractures or diseases that limit blood supply to bone tissue. Avascular necrosis affects about 20% of people without any clear cause.

The following are some of the known causes of avascular necrosis:

1. Traumatic avascular necrosis: It can occur if a bone is broken or a joint is dislocated.
2. Nontraumatic avascular necrosis: This occurs when blood supply to your bone tissue is blocked by an illness or medical condition. The same bones on both sides of the body are frequently affected by nontraumatic avascular necrosis. If you have avascular necrosis in your right shoulder, it’s likely that you’ll also have it in your left.
3. Fat deposits in blood vessels: Lipids (fat) can obstruct small blood arteries, decreasing blood flow to the bones. 
4. Certain Diseases: Medical disorders such as sickle cell anaemia and Gaucher’s disease can also cause a reduction in blood flow to the bones.

How is Diagnosis Done?

Your doctor will most likely press around your joints during a physical exam to check for soreness. Your doctor may also move your joints around in different positions to examine if your range of motion has been limited.

Joint pain can be caused by a variety of conditions. Imaging tests can assist in determining the cause of discomfort. Among the possibilities are:

1. X-Rays
2. CT Scans and MRIs
3. Radionuclide Bone Scan
4. Biopsy
5. Functional evaluation of Bone

How Hip Avascular Necrosis Treatment is Done?

1. Although nonsurgical treatments including anti-inflammatory drugs, activity adjustments, and crutches can help reduce discomfort and delay the progression of the condition, surgical treatments are the most effective. Patients with hip avascular necrosis who are diagnosed early enough (before the femoral head collapses) may be candidates for hip preservation surgery.

2. Medications and therapy may help to alleviate symptoms in the early stages of avascular necrosis.

3. If hip avascular necrosis has progressed to the point that the femoral head has collapsed, total hip replacement is the most effective treatment. Your doctor will remove the damaged bone and cartilage, then replace it with new metal or plastic joint surfaces to restore hip function.

4. When osteonecrosis is discovered after a bone has collapsed, core decompression is rarely effective in preventing further collapse. In this case, a total hip replacement is the best option for the patient. In the majority of patients with osteonecrosis, total hip replacement is beneficial in alleviating pain and restoring function.

5. Your healthcare professional will decide on a specific treatment for avascular necrosis depending on the following factors:

Your age, general health, and medical history are all factors to consider.

1. Disease’s severity
2. The amount and location of bone that is affected
3. The disease’s underlying cause
4. Your ability to tolerate certain medications, surgeries, or therapies
5. Expectations regarding the disease’s progression
6. Your point of view or preference

The goal of treatment is to increase functionality while also preventing additional bone or joint deterioration. To keep joints from breaking down, treatments are required, which may include:

1. 1. Assisted Devices
   2. Medicines
   3. Core Decompression
   4. Bone Graft

Joint Replacement

Hip preservation is the best option among all possible treatments, according to a few experienced surgeons. Hip preservation surgery can lower the risk of developing early arthritis and the need for hip replacement surgery later on, in addition to relieving hip discomfort and restoring normal function.

Only if you meet the following criteria after having testing you are eligible for hip preservation surgery: 

1. Have a high level of physical activity.
2. Have mild arthritis and are of sufficient skeletal maturity to withstand surgery
3. Have a high level of resistance to infections in the hip joint
4. When all previous treatments have failed

Words from Dr. Narender Kumar Magu, an internationally renowned Orthopaedic Surgeon.

Hip preservation was created in response to technological restrictions in hip replacement. Hip preservation, especially in young patients, is a strategy to avoid or delay the onset of osteoarthritis or other degenerative joint disorders. Dr Magu provides a comprehensive range of Hip Preservation Surgeries, which are a safe and effective alternative to Total Hip Replacements for active individuals.

Dr. N.K. Magu is an internationally recognised orthopaedic surgeon who specialises in complex orthopaedic treatments such as hip disorders and pelvic-acetabular fracture reconstruction. His Biological Fixation of Acetabular Fractures and Proximal Femoral Osteotomies procedures have been globally acknowledged. These procedures allow patients to keep their native hip and femoral head, improve joint motion, and reduce pain, all of which helps to avert a partial or total hip replacement.