[Multiple osteonecrosis. Update and case report].

Multifocal osteonecrosis is defined as the presence of osteonecrosis in three or more osseous sites. It is an infrequent entity representing less than 3% of cases among osteonecrosis patients. Multifocal osteonecrosis has been associated with systemic diseases, with patients at highest risk being those with lupus erythematosus, transplant recipients and those with haematological disorders or prolonged high-dose glucocorticoid treatment. The area most prone to disturbances is the femoral head. The pathogenesis of this particular disorder has not been fully defined, although several risk factors have been identified. We report the case of a young woman with abnormal hemostatic factors and a history of glucocorticoid and oral contraceptive therapy who developed bilateral hip osteonecrosis, followed by shoulder ON. The present article also provides an extensive literature review of the aetiology and treatment of multifocal ON.