 B Intraoperative phase All subjects will be receive propofol infusion beginning at 50 mgkgmin and titrated to a Richmond Agitation-Sedation Scale score of -1 to -3 drowsy to moderate sedation. Dexamethasone 10 mg IV and ketamine 0.25 mgkg IV up to 40 mg total will be administered as part of the standard multimodal regimen. If required, subjects may receive fentanyl 25 mcg IV as needed to treat discomfort. No joint infiltration will be performed by the surgeon. 