Osteonecrosis (ON) is a degenerative manifestation of bone in which the cellular component dies following an interruption of the blood supply.

Causes

Reduced blood supply can be caused by:

  • Joint or bone trauma. An injury, such as a dislocated joint, can cause nearby blood vessels to break down. Cancer treatments involving radiation can also weaken bones and damage blood vessels.
  • Fat deposits in blood vessels. Fat (lipids) can block small blood vessels. This can reduce blood flow to the bones.
  • Some diseases. Sickle cell anemia and Gaucher disease can also reduce blood flow to the bones.

Risk factors

  • Knee joint trauma
  • Steroids
  • Cushing’s disease
  • alcohol abuse
  • Connective tissue diseases, including systemic lupus erythematosus
  • Osteomyelitis
  • Human immunodeficiency virus infection
  • Organ transplantation
  • Hemoglobinopathies, including sickle cell disease
  • Hyperlipidemia
  • Gout
  • Renal failure
  • Pregnancy
  • Radiation therapy

Classification