The purpose of this study is to evaluate the efficacy and safety of various doses of YM150 (the experimental drug) compared to enoxaparin in the prevention of venous thromboembolism in patients that are undergoing elective hip replacement surgery.

Inclusion Criteria:

• Subject is scheduled for elective hip replacement surgery

Exclusion Criteria:

• Subject has active bleeding or any condition associated with increased risk of bleeding
• Subject has had major trauma or surgery within 3 months before planned hip replacement surgery or requires major surgery or other invasive procedures with potential for uncontrolled bleeding during the study
• Subject has had an MI or stroke within 3 months before planned hip replacement surgery