What are the common causes of osteonecrosis?

Alcohol
Sickle cell disease, SLE, and scleroderma
Endogenous or exogenous steroids
Pancreatitis
Trauma (fracture of the femoral neck or navicula, dislocation of the talus)
Idiopathic (Legg-Calvé-Perthes disease, Blount's disease, Kienböck's disease) and iatrogenic (radiation therapy, steroid therapy)
Caisson disease (the bends)

ASEPTIC