32 patients scheduled for total knee arthroplasty were randomized to thromboprophylaxis with either rivaroxaban 10mg daily or aspirin 300mg daily for 14 days after surgery. Patients were assessed for deep vein thrombosis rate, local complication rate, systemic complication rate, reoperation rate, mortality rate, postoperative blood loss, and hemoglobin and hematocrit drop. Of primary consideration, analyses demonstrated no significant difference in the rate of deep vein thrombosis between groups, as well as no significant difference in 48-hr postoperative blood loss between groups.