The Causes of Osteonecrosis

Osteonecrosis, also commonly known as avascular necrosis, is a medical condition that is characterized by the death of the tissues present in the bone due to lack of blood supply. Osteonecrosis most often affects the femur, causing severe pain in the hip region; however it can occur in any other bones in the body as well. Avascular necrosis often makes the bones very fragile, leading to cracks or fractures. The American Academy for Orthopedic Surgeons has estimated that 10,000 to 20,000 Americans are diagnosed and treated for osteonecrosis each year. The patient's condition generally worsens with the passage of time, making osteonecrosis a progressive process that requires treatment and medications throughout the patient's life. There are various causes or risk factors leading to osteonecrosis.

Trauma

• Trauma or injury to a bone is often considered to be one of the major factors contributing to the development of osteonecrosis in individuals. Injuries such as fracture of the bones or a dislocated joint often result in damage to the blood vessels, ultimately resulting in the inadequate and reduced supply of blood to the bones. This increases the chances of developing osteonecrosis.

Corticosteroids

• Excessive use of corticosteroids is another major factor leading to the development of osteonecrosis. According to the staff of the Mayo Clinic, people who take large doses of corticosteroids such as prednisone over a long period of time have an increased risk of developing avascular necrosis as compared to those who do not take these drugs. However, the exact mechanism for this increased risk is still not clearly known.

Consumption of Alcohol

• Consumption of large amounts of alcoholic beverages also leads to the development of osteonecrosis. Increased consumption of alcoholic drinks often causes accumulation of various fatty substances on the walls of the blood vessels, reducing the flow of blood to the organs and the bones, and thereby increasing the probability of developing osteonecrosis.

Medical Conditions

• According to the Mayo Clinic, individuals suffering from sickle cell anemia, lupus, "the bends" (also known as decompression disease) and Gaucher's syndrome are often at an increased risk of developing osteonecrosis as compared to others who do not have these disorders.

Less Common Causes

• Less common causes of osteonecrosis include cancer treatments such as chemotherapy and radiation, and genetic and hereditary factors.