This study was performed to determine whether abnormalities of thrombosis and fibrinolysis are associated with nontraumatic osteonecrosis of the femoral head.

A case-control study was conducted in 24 patients with nontraumatic osteonecrosis of the femoral head. These patients were matched with 24 controls for gender, age (1-year range), and time of presentation (1-year range). The study included 19 men and 5 women, and the mean age of patients and controls was 46 years (range, 16-68 years). Eight patients had idiopathic osteonecrosis and the remaining 16 patients had secondary osteonecrosis. Protein C activity, protein C antigenicity, protein S activity, protein S antigenicity, antithrombin III, anticardiolipin antibody-Ig G, anticardiolipin antibody-Ig M, lupus anticoagulant, plasminogen, tissue plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), and lipoprotein(a) were investigated.

Protein C antigenecity and protein S antigenecity, which have been known to decrease in osteonecrosis patients, were increased in patients compared with those of controls (P<0.05). No significant differences were found in the levels of other thrombotic or fibrinolytic factors. In a subgroup of 16 patients with secondary osteonecrosis, the level of anticardiolipin antibody immunoglobulin M was greater than in the respective controls (P<0.05).

The results of the current study suggest that abnormalities in the coagulation and fibrinolytic system are not associated with the pathogenesis of osteonecrosis of the femoral head.