Hypercoagulability and hypofibrinolysis in primary osteoarthritis.

Histologic evidence of venous thrombosis and lipid abnormalities have previously been reported in osteoarthritis. Hypofibrinolysis has been recorded in patients with ischemic necrosis of bone, and it has been proposed as a major cause of osteonecrosis. This study determines whether systemic evidence of coagulation and lipid abnormalities could be detected in osteoarthritis. Global and specific tests were used to assess coagulability and fibrinolysis in 44 patients with degenerative osteoarthritis of the hip and 52 matched control subjects. In patients with osteoarthritis, an increase in factor VIIlc, increased platelet sensitivity over a range of adenosine diphosphate concentrations (0.05 micromol/L-4 micromol/L) and elevated D dimer levels were found. Euglobulin clot lysis time was prolonged in this group and plasminogen activator inhibitor Type 1 activity was increased. Relative hyperlipidemia was observed in the osteoarthritis group, with increased cholesterol, low density lipoprotein cholesterol, and triglyceride levels. It is concluded that there is a hypercoagulable and prothrombotic condition in osteoarthritis, with hypofibrinolysis and indirect evidence of increased fibrin generation. The possible contribution of lipid abnormalities to hemostatic imbalance in osteoarthritis is discussed.