Osteonecrosis and bone infarction in association with Behcet's disease: report of two cases.

We describe two cases with Behcet's disease (BD) developing osteonecrosis or bone infarction. One patient developed the extensive bone infarction of the left knee without the use of corticosteroids. The other patient had osteonecrosis at the right femoral head. He had had a past history of significant corticosteroid administration to treat several complications of BD such as central nervous system involvement, uveitis, gastrointestinal involvement, and pulmonary involvement. Anticardiolipin (aCL) antibodies were positive in these two patients. One was IgG type, and the other was IgM type. However, it remains unclear that there is relationship between the presence of aCL antibodies and occurrence of osteonecrosis.