A Phase 3 Randomized, Double-Blind Active-Controlled (Enoxaparin), Parallel-Group, Multi-Center Study to Evaluate the Safety and Efficacy of Oral Apixaban in Subjects Undergoing Elective Total Knee Replacement Surgery

The purpose of this study is to learn if apixaban can prevent blood clots in the leg (deep vein Thrombosis \[DVT\]) and lung (pulmonary embolism \[PE\]) that sometimes occur after knee replacement surgery and to learn how apixaban compares to enoxaparin (Lovenox®) for preventing these clots. The safety of apixaban will also be studied.