Plasma levels of coagulation inhibitors, fibrinolytic markers and platelet-derived growth factor-AB in patients with failed hip prosthesis

We studied the plasma levels of coagulation inhibitors, of fibrinolysis and PDGF-AB, in patients with aseptic loosening of the hip replacement. 23 patients having loose hip prostheses were compared to patients having 15 stable hip prostheses, and 26 undergoing primary hip replacement. The levels of the coagulation inhibitors antithrombin III and protein C were determined by chromogenic assays. Fibrinolysis was evaluated by the changes in fibrin degradation products (D-dimer), determined by enzyme immunoassay, and in the plasminogen activator inhibitor-1 (PAI-1), by enzymatic assay. PDGF-AB was determined by enzyme immunoassay. In patients with failed prostheses, we found fibrinolysis activation, as shown by a statistically significant increase in D-dimer and a significant decrease of PAI-1. No significant differences were obseved in antithrombin III, protein C, and PDGF-AB. PAI-1 and D-dimer assays in failed prostheses may be useful for the pathogenetic evaluation, because the continuous inflammatory stimulus associated with fibrin deposition may also affect the systemic levels.