• A composite endpoint consisting of total Venous Thromboembolic Event (VTE) and all cause mortality during the treatment period.
  

• Secondary efficacy endpoints (during the treatment period): Composite of major VTE (defined as proximal DVT and PE) and VTE related mortality Proximal DVT Total DVT Symptomatic DVT Pulmonary Embolism (PE) Death
  

This is a double-blind, multi-centre, randomized, parallel-group placebo-controlled study to evaluat e the efficacy and safety of BIBR 1048 (Dabigatran etexilate) oral administration, as well as its do se-response, in preventing venous thromboembolism (deep vein thrombosis and pulmonary embolism) in p atients with elective total knee replacement surgery. There are three administration groups in total

• the BIBR 1048 110 mg, 150 mg and 220 mg once daily administration groups and the placebo group, wi th 100 cases in each group (total of 400 cases), and the study drug will be randomly allocated to pa tients in each group. The administration period is 11-14 days after total knee replacement surgery, and the study drug will be given once daily.

Study Hypothesis:

This trial aims is to demonstrate the effectiveness of BIBR 1048 (Dabigatran ete xilate), compared with placebo, in prevention of venous thromboembolism in patie nts with primary elective total knee replacement surgery. For the primary endpoi nt (total VTE and all cause mortality), superiority of BIBR 1048 (Dabigatran ete xilate) to placebo will be tested.

Comparison(s):

For the primary comparison the rates of total venous thromboemobolism events (VT E) and all-cause mortality during the treatment period will be compared.