Menu
Avascular Necrosis
Best Avascular Necrosis Surgeon in Mumbai
What is Avascular Necrosis (Osteonecrosis)?
Avascular Necrosis (AVN), also known as osteonecrosis of the hip means the death of a segment of the bone in the femoral head. It is a condition that results from an interruption of blood supply to the bone. The bone is a living tissue that requires blood. A lack of blood flow to the bone can lead to the death of bone tissue If not treated, it can eventually cause the bone to collapse. The condition also causes the bone to lose its smooth shape, leading to severe arthritis.
The most commonly affected joint is the hip bone, but other common sites are the knees, shoulder, and ankles. vascular Necrosis may be bilateral in about 80% of patients. Especially, those who are having difficulty movement of the hip joint like flexing, abducting, and internally rotating the hip. Those are often signs of femoroacetabular impingement (FAl) which could include pincer, cam, lesions (abnormal tissue), or even arthritis of the hip.
But, we have seen some people in the past who have developed avascular necrosis which is a loss of vascularity to the head and neck of the femur. Basically, the bone becomes necrotic and dies off. It can ultimately fracture with very little activity. Multifocal avascular necrosis is a disease involving three or more sites. Such as the hip, the knee, the shoulder, and the ankle, which occurs in about 3% of patients.
What Causes Avascular Necrosis?
Osteonecrosis often results from an underlying health condition or injury. Healthy people have a lower risk of developing the condition.
Possible causes may include:
- Dislocation or fracture of the thigh bone
- Long-term use of corticosteroids such as prednisone
- Dislocated joint
- Alcoholism
- Blood clots, inflammation, and damage to arteries
- Chemotherapy or radiation therapy
- Organ transplants, especially kidney transplant
Medical conditions that cause the condition may include:
- Autoimmune diseases
- Diabetes
- HIV/AIDS
- Gaucher’s disease
- Stickle cell anemia or other blood condition
- Pancreatitis
Covid 19 infection is emerging as a major cause of vascular Necrosis. There is no scientific evidence to prove that covid-19 infection is the cause of AVN. However Covid-19 is associated with increased clotting tendency and the use of blood thinners in the post-recovery phase is common in the recovery phase of covid-19 to prevent clots in major organs like the heart, brain, and arteries of arms and legs. So AVN of the hip may be a manifestation of covid-19 infection. To complicate matters further, Steroids used in the treatment of Covid-19 can also cause Bone death.
What Symptoms of Avascular Necrosis?
In the early stage of the condition, many people have no symptoms but as the disease progresses, symptoms may occur and may include mild or severe pain in the affected region. Pain occurs when you put weight on the affected bone. Severe pain that interferes with the ability to use the joints or move.
What is the best treatment for avascular necrosis?
The aim of the treatment is to improve the function of the affected bone, prevent other bone loss and reduce pain. There are some factors that determine the kind of treatment that you are given, they are:
- Age
- The cause
- Amount of bone damage and its location
If the cause of the disease is identified, treating the underlying medical conditions may be necessary. In the early stage, medication and therapy may be needed to relieve symptoms, Your doctor may recommend:
- Blood thinners such as warfarin may be prescribed to dissolve clots. If your osteonecrosis is caused by blood clots.
- Anti-inflammatory medications may be prescribed if your condition is caused by an inflammation of the arteries.
- Reducing pressure and stress on the affected bone. This can slow down the damage. This may be achieved by using crutches and can be used if your hip, ankle, or knee is affected.
- Exercises to improve the range of motion in your joint.
- Early-stage of the disease using bisphosphonate is utilized.
- Bisphosphonate can decrease the risk of collapse and decrease pain.
SURGERY IN EARLY AVN:
If you are lucky for AVN to be diagnosed at an early ( pre-collapse) stage. Then 2 surgeries can be considered.
- Core Decompression: This surgery is indicated for pain relief but has no role in saving of femoral head. It is responsible for pain relief. It can be used when the risk of collapse of the femoral head is low.
- Ossogrow: Ossogrow is the world’s first FDA-approved bone implant made from a patient’s own cells. It has been shown to improve the survival of the femoral head in cases where the chance of collapse is very high.
Stage 1 and stage 2, will be constant head preservation procedures. Decompression is the drilling of the lesion and removal of the necrotic bone with or without a bone graft.
Bone Graft:
- Can be an autograft, a vascularized bone graft can be done by vascularized free fibular graft.
Core decompression for stage 1 and stage 2:
- Can make a single large hole or multiple small holes in the femoral head.
- It decompresses the head and stimulates a healing response.
- The lesion is usually anteriorly and superiorly.
- For core decompression use about 5-7mm drill with or without a bone graft
Vascularized Fibular Graft:
- Is done in younger patients
- Show about 80% success rate at 5-10 years follow-up.
Complications of Vascularized Fibular Graft:
- Donor site pain and leg dysfunction.
- The patient may have motor weakness sensory deficit and tibial stress fracture from the side the graft is taken.
- The vascularized fibular graft is less predictable in patients more than 40 years old. If after the hip preserving procedure the patient continues to complain of pain, the femoral head continues to complain of pain, and the femoral head continues to collapse, then there will be total hip arthroplasty. In general, the collapse of the femoral head or if there are acetabular changes, especially if the pain is resistant to medical treatment, then this an indication of total hip arthroplasty.
Stage 3 and Stage 4:
- Total hip arthroplasty (cementless cup stem).
- Total hip arthroplasty is considered to be the traditional procedure for advanced stages of osteonecrosis of the hip.
- Total hip arthroplasty provides predictable success and relief of pain.
- The outcome of total hip replacement in younger patients with osteonecrosis, the result is not as good as an older patient who had total hip arthroplasty for osteoarthritis.
- Nonsteroidal anti-inflammatory drugs. Medications, such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve) might help relieve the pain associated with vascular necrosis.
- Osteoporosis drugs
- Cholesterol-lowering drugs
- Blood thinners
How Is Avascular Necrosis Diagnosed?
During a physical examination, your doctor will likely check your joints for tenderness. The joint may also, be moved through different positions to see if your range of motion has decreased. To get a proper look at your bones, one or more imaging tests may be recommended.
- X-rays: X-rays usually appear normal in the early stage but can reveal changes to the bone that occur in the late stage of the condition.
- MRI (Magnetic Resonance Imaging) or CT scan: This type of imaging can show early changes in your bone and can help the doctor to see how much of the bone is affected.
- Bone scan: This type of scan requires that your doctor insert a small amount of harmless radioactive into a vein. This substance lets the doctor see the inside of your bone. .
Stages of vascular Necrosis of the Hip
The Ficat classification is a commonly used system to stage avascular necrosis of the hip.
- Stage 1: has a normal x-ray but MRI reveals the dead bone.
- Stage 2: This can be seen on regular x-ray but there is no collapse of the femoral ball.
- Stage 3: shows signs of collapse (called a crescent sign) on x-ray.
- Stage 4: has collapsed on x-ray and signs of cartilage damage (osteoarthritis).
What Is the Treatment for Avascular Necrosis?
- Avoiding injury to a bone that is affected by avascular necrosis is the first line of treatment.
- This can include non-weight-bearing (crutches), etc. when a weight-bearing joint is involved.
- The aim is to attempt to preserve the affected joint and avoid joint replacement, when possible, especially in young individuals.
- Treating any underlying cause of avascular necrosis (stopping smoking and alcohol intake, etc.) and management of underlying diseases are essential to minimize the progression of the disease and prevent the involvement of other bones.
- Bisphosphonate medications, such as alendronate (Fosamax), have been shown to reduce bone pain and improve function in patients with vascular necrosis.
- Additionally, medications to lower blood fats (lipids, including cholesterol and triglycerides) and blood-thinning medications (anticoagulants) have been used effectively in certain situations.
- Joint-preservation operations that delay the need for total joint replacement include measures that allow improved blood supply to the affected bone. These procedures are typically used in early Avascular Necrosis of the hip and include removal of a core of bone from the head of the femur the bone of the hip (core decompression) as well as local bone-grafting procedures.
What Is the Prognosis for Avascular Necrosis?
The underlying cause as well as the amount and location of bone affected by avascular necrosis to some degree determine the outcome. Larger areas of vascular necrosis often cannot be repaired by joint-preserving methods and ultimately joint replacement is necessary. When an underlying disease or condition is the cause, optimal treatment of that disease or condition can decrease the chances of worsening the vascular necrosis or involvement of other areas of bone.