In 2011, 140 000 total hip replacements were performed and bleeding remains one of the major complications responsible for significant morbidity. This study will evaluate a new treatment to prevent bleeding due to this surgery. Indeed, the tranexamic acid (Exacyl) will be used in two modes of administration (standard or extended) versus placebo combined with a Rivaroxaban treatment at a dose of 10 mg / day for 35 days.