Inclusion Criteria:

• Must have undergone reparative surgery within 72 hours after unilateral hip fracture, defined as fracture of the upper third of either femur
• Must have started standard prophylactic treatment for VTE with low molecular weight heparin (LMWH) or heparin before surgery or within 24 hours after hip fracture surgery, and continued treatment with LMWH or heparin for at least five days, but not more than nine days, after surgery
• Last dose of LMWH or heparin must have been administered at least 12 hours, but not more than 48 hours, before dosing with study drug
• Females must have a negative serum pregnancy test
• Must weigh at least 45 kg
• Must demonstrate the mental and physical ability and willingness to follow all study-specific instructions
• Must be able to read, comprehend and sign the Ethics Committee-approved informed consent form

Exclusion Criteria:

• Evidence of active bleeding
• Clinical signs of VTE
• Any medical requirement for (or intention to use) continued anticoagulation after randomization through the end of study
• History of intracranial bleeding, hemorrhagic stroke, or gastrointestinal bleeding within 3 months of study start
• Presence of active malignant disease
• Hip fracture associated with multiple trauma, that places patient at excessive risk for hemorrhage or organ system failure, or that may make it difficult or impossible to perform bilateral lower limb venography
• Intention to take aspirin at doses greater than 325 mg/day
• Hemoglobin < 5.45 mmol/L (9 g/dL), hematocrit < 29%, or a platelet count < 100,000/mL at the screening visit
• Elevated ALT or AST level > 3.0 times the ULN, or an elevated total bilirubin > 1.5 the ULN at the screening visit
• Creatinine > 180 mmol/L (2.0 mg/dL) at the screening visit
• Any other laboratory value at screening that the Investigator considers to be clinically significant and warrants exclusion from the study
• Patient is currently breast feeding a child and wishes to continue breast feeding
• Previous allergy to contrast material or any other contraindications to perform bilateral lower limb venography
• The use of another investigational drug within 28 days of study entry