Understanding Avascular Necrosis: Causes, Symptoms, and Treatment Options

Hugo Benalcazar

Medically reviewed by Hugo Benalcazar, Northwestern University on August 31st, 2023.

Key Takeaways

  • Bone death occurs within 2-3 hours of complete blood supply interruption, with the femoral head (hip joint) affected in 80% of cases due to its limited collateral circulation.
  • Pain typically develops 6-18 months after the initial bone damage, starting as a dull ache during weight-bearing activities and progressing to constant, severe pain as the joint collapses.
  • Long-term corticosteroid use (equivalent to 20mg+ prednisone daily for several months) and consuming more than 3 alcoholic drinks per day are the leading preventable risk factors.
  • Core decompression surgery has 60-80% success rates when performed before joint collapse occurs, but delays beyond stage III disease often require total joint replacement.
  • MRI detects bone death 6-12 months earlier than X-rays, which only show changes after significant structural damage has already occurred.

Avascular necrosis (AVN), also known as osteonecrosis, is a condition that occurs when bone tissue dies due to a lack of blood supply. If left untreated, AVN can cause the affected bone to collapse, leading to severe pain and joint damage. While AVN can affect any bone, it most commonly occurs in the hip, shoulder, knees, and ankles.

Symptoms of Avascular Necrosis

In the early stages of AVN, you may not experience any symptoms. However, as the condition progresses, you may start to feel pain in the affected area, especially when putting pressure on the bone. Over time, the pain may become constant and severe, making it difficult to use the affected joint.

Causes and Risk Factors for Avascular Necrosis

Several factors can increase your risk of developing AVN, including:

  • Alcohol abuse

  • Long-term use of corticosteroids

  • Trauma or injury to the affected area

  • Certain medical conditions, such as sickle cell disease, lupus, and HIV

  • Radiation therapy or chemotherapy

Understanding Avascular Necrosis: Causes, Symptoms, and Treatment Options

Diagnosing Avascular Necrosis

To diagnose AVN, your doctor will perform a physical exam and may order imaging tests such as X-rays, MRI, CT scans, or bone scans. These tests can help identify changes in the bone that are characteristic of AVN, even in the early stages of the disease.

Treatment Options for Avascular Necrosis

Treatment for AVN depends on several factors, including your age, the stage of the disease, and the location and extent of the bone damage. In the early stages, treatment may involve medications to relieve pain, limiting the use of the affected joint, and using crutches to reduce weight-bearing. Your doctor may also recommend range-of-motion exercises to help maintain joint mobility.

In more advanced cases, surgery may be necessary. Surgical options include:

  • Core decompression to relieve pressure and stimulate new blood vessel growth

  • Bone grafts to replace damaged bone with healthy bone from another part of the body

  • Osteotomy to reshape the bone and reduce stress on the affected joint

  • Total joint replacement to remove the damaged joint and replace it with an artificial one

Preventing Avascular Necrosis

While not all cases of AVN can be prevented, there are steps you can take to reduce your risk, such as:

  • Limiting alcohol consumption

  • Managing cholesterol levels

  • Using corticosteroids only as directed by your doctor

  • Avoiding smoking

If you suspect you may have AVN, it's important to seek medical attention as soon as possible. Early diagnosis and treatment can help prevent further bone damage and improve your long-term outlook. With proper care and management, many people with AVN are able to maintain joint function and enjoy a good quality of life.

For more information on avascular necrosis, visit:

The Bottom Line

Early detection through MRI imaging is critical since successful joint-preserving treatments are only effective before bone collapse occurs, typically within the first 1-2 years. The condition progresses silently in early stages, making prompt evaluation of persistent joint pain essential. If you're experiencing unexplained hip, shoulder, or knee pain, especially with risk factors present, Doctronic can help you get the imaging and specialist consultation needed for timely diagnosis.

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