Most common risk factors:
(1) alcoholism
(2) Cushing's disease
(3) corticosteroid use
Additional risk factors:
(4) trauma with fracture
(5) sepsis
(6) radiation
(7) thermal or electrical injury
(8) Caisson's disease in compressed air workers and divers
(9) unstable hemoglobinopathies (sickle cell disease, etc.)
(10) hemophilia
(11) hypercoagulable state
(12) Gaucher's disease
(13) systemic lupus erythematosus
(14) rheumatoid arthritis
(15) systemic sclerosis
(16) vasculitis
(17) organ transplantation
(18) chronic dialysis
(19) HIV infection
(20) pancreatitis
(21) chronic liver disease
(22) hypertriglyceridemia
(23) pregnancy, especially during the third trimester
(24) Weber-Christian disease
(25) gout
(26) osteomalacia, osteopenia, osteoporosis
(27) idiopathic
Mechanisms:
(1) interruption of extraosseous arterial blood supply
(2) interruption of intraosseous sinusoidal circulation
(3) extravascular compression of sinusoidal circulation
(4) increased bone marrow pressure