Which are the causes of Osteonecrosis?

Osteonecrosis, also known as avascular necrosis, is a condition that occurs when there is a loss of blood supply to a bone, leading to its death. This can result in pain, limited mobility, and even bone collapse. While the exact cause of osteonecrosis is not always clear, there are several factors that can contribute to its development.

1. Trauma and Injury

Trauma or injury to a bone can disrupt the blood supply, causing osteonecrosis. Fractures, dislocations, or any other form of significant trauma can damage the blood vessels that nourish the bone, leading to its death over time.

2. Steroid Use

Prolonged or high-dose use of corticosteroids is a well-known risk factor for osteonecrosis. Steroids can interfere with the body's ability to maintain healthy bone tissue by reducing blood flow and impairing bone repair mechanisms.

3. Alcohol Abuse

Excessive alcohol consumption can weaken bones and impair blood circulation, making them more susceptible to osteonecrosis. Alcohol abuse can also lead to fatty deposits in blood vessels, further compromising blood flow to the bones.

4. Medical Conditions

Several medical conditions can increase the risk of osteonecrosis:

• Lupus and other autoimmune diseases can cause inflammation and damage to blood vessels.


• Sickle cell disease and other blood disorders can lead to blockages in blood vessels, reducing blood flow to the bones.


• Diabetes can affect blood circulation and increase the risk of osteonecrosis.


• Hypercoagulable disorders that cause excessive blood clotting can disrupt blood flow to the bones.

5. Radiation Therapy

High-dose radiation therapy can damage blood vessels and decrease blood flow to the bones in the treated area. This can result in osteonecrosis, which may occur months or years after the radiation treatment.

6. Joint Disorders

Certain joint disorders can increase the risk of osteonecrosis:

• Osteoarthritis and other degenerative joint diseases can cause joint damage and impair blood flow.


• Rheumatoid arthritis and other inflammatory joint diseases can lead to joint inflammation and damage blood vessels.


• Joint dislocation or instability can disrupt blood supply to the bone.

It is important to note that osteonecrosis can also occur without any identifiable cause, known as idiopathic osteonecrosis. Additionally, the risk of developing osteonecrosis can vary depending on individual factors such as age, gender, and overall health.