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 p roposed as a major cause of osteonecrosis. This study determines wheth er systemic evidence of coagulation and lipid abnormalities could be d etected in osteoarthritis. Global and specific tests were used to asse ss coagulability and fibrinolysis in 44 patients with degenerative ost eoarthritis of the hip and 52 matched control subjects, In patients wi th osteoarthritis, an increase in factor VIIIc, increased platelet sen sitivity over a range of adenosine diphosphate concentrations (0.05 mu mol/L-4 mu mol/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 o bserved in the osteoarthritis group, with increased cholesterol, low d ensity lipoprotein cholesterol, and triglyceride levels. It is conclud ed that there is a hypercoagulable and prothrombotic condition in oste oarthritis, with hypofibrinolysis and indirect evidence of increased f ibrin generation. The possible contribution of lipid abnormalities to hemostatic imbalance in osteoarthritis is discussed.