Table 1.

New developments on pathogenesis of nontraumatic osteonecrosis and its clinical significance.

New findings	Clinical significance
Steroids enhance adipogenesis and inhibit osteogenesis and angiogenesis by marrow stem cells [53, 54, 56]	Therapeutic modulating marrow stem cell Statins have shown therapeutic effects [54, 56, 74]
Alcohol stimulate adipogenesis and inhibit osteogenesis by marrow stem cells [40, 65]	Therapeutic modulating marrow stem cell
Heritable hypofibrinolysis and thrombophilia [32, 34, 40, 50, 72]	Anticoagulation therapy is effective [75]
Genetic associations
Mutations in the COL2A1 gene [30]	Familial high risk group
Polymorphisms in alcohol metabolizing enzyme gene [29]	High risk subgroup
Polymorphisms in the multidrug resistance gene 1 [73]	Screening high risk patients [73]