Fat embolism and osteonecrosis.

Clinical and experimental data accumulated within the past 2 decades explain the relationship between fat embolism and osteonecrosis, which now appears to be more causal than coincidental. Evidence for fatty liver, coalescence of endogenous plasma lipoproteins, and/or disruption of depot or marrow fat, all resulting in continuous or intermittent fat embolism, is related to 13 different clinical conditions associated with osteonecrosis, most recently including pregnancy, carbon tetrachloride poisoning, and possibly Legg-Calvé-Perthes disease. Intraosseous fat embolism, then, appears to trigger a three-phase thrombotic process of focal intravascular coagulation that results in osteonecrosis.