The object of present study was to investigate the relationship between LCPD and the abnormality of certain plasma proteins affecting clot mechanism and fibrinolysis in patients with LCP disease.

Twenty-five consecutive patients who had been diagnosed as LCP disease were matched with twenty-five controls for gender, age (2-year range) , and the time of presentation (1-year range) . There were twenty-three boys and two girls. The mean age of the children when the LCP disease was diagnosed was 6.7 years ( range, 2.1-12.8 years) , and the mean age at the time of the present study was 7.9 years ( range, 3.4 - 13 year) . Thrombotic disorders were investigated for protein C activity/antigenicity, protein S activity/antigenicity, antithrombin III, anticardiolipin antibody Ig G, anticardiolipin antibody Ig M, lupus antibody. Fibrinolytic disorders were investigated for tissue type plasminogen activator (t-PA) , plasminogen, plasminogen activator inhibitor-1 (PAI-1) , alpha 2 plasmin inhibitor, lipoprotein (a) . Wilcoxon rank sum test was used for the comparison.

There was no significant difference in coagulation system and fibrinolytic system between patients and controls.

Our results suggest that abnormality in coagulation and fibrinolytic system is not associated with Legg-Calv -Perthes disease.