DECREASED FIBRINOLYTIC POTENTIAL IN PATIENTS WITH IDIOPATHIC AVASCULAR NECROSIS AND TRANSIENT OSTEOPOROSIS OF THE HIP

A thrombotic etiology has been suggested as the cause of idiopathic av ascular necrosis of the hip, although the underlying pathophysiologica l mechanisms are unknown. Transient osteoporosis of the hip has also b een suggested to represent bone marrow edema that may be related to is chemia. We evaluated four patients with idiopathic avascular necrosis and one patient with transient osteoporosis of the hip for thrombotic potential placing a special emphasis on the fibrinolytic system. All f ive patients had identifiable abnormalities of fibrinolysis. Four pati ents had elevated levels of plasminogen activator inhibitor (PAI-1) an d one patient had an inadequate increase in tissue plasminogen activat or (tPA) post venous occlusion. Serum triglycerides were increased in three of the patients. These findings suggest an association between d ecreased fibrinolytic potential and the subsequent development of avas cular necrosis and transient osteoporosis of the hip. These patients s hould have an evaluation of the fibrinolytic system with tPA and PAI-1 levels as well as a lipid profile. (C) 1993 Wiley-Liss, Inc.