Avascualr necrosis (AVN), also called osteonecrosis or aseptic necrosis, is a condition that occurs when there is loss of blood to the bone. The femoral head is the most common location for AVN to occur.

Etiology can be remembered by the following mnemonic:

GIVE INFARCTS

• Gaucher disease
• idiopathic (Legg-Calvé-Perthes, Köhler, Chandler)
• vasculitis (SLE, polyarteritis nodosa, rheumatoid arthritis)
• environmental (frostbite, thermal injury)
• irradiation
• neoplasia (associated coagulopathy)
• fat (prolonged corticosteroid use increases marrow)
• alcoholism
• renal failure and dialysis
• Caisson disease
• trauma (femoral neck fracture, hip dislocation)
• sickle cell disease