Osteonecrosis secondary to antiphospholipid syndrome: a case report, review of the literature, and treatment strategy.

Osteonecrosis is commonly present in patients with antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). Treatment of this condition remains extremely controversial. We present a treatment strategy of avascular necrosis of the knee in a patient with catastrophic antiphospholipid syndrome with a history of SLE and APS. Aggressive treatment with 12 rounds of plasmapheresis, intravenous immunoglobulin, rituximab, and cyclophosphamide led to the patient's recovery with no recurrence of symptoms during 16 months of follow up. In this report, we further discuss the pathogenesis of osteonecrosis and current understanding of the treatment of this disease.