Aprepitant to Improve Same Day Discharge for TKA

The purpose of this research is to study whether adding an FDA approved medication called aprepitant (a medication given to patients like you to reduce or eliminate nausea and vomiting) to the usual treatment to prevent nausea and vomiting given to patients during knee replacement surgery helps more patients go home on the same day of surgery (before midnight) by eliminating nausea and vomiting.