We calculated that 238 patients (119 in each group) were required to detect a 50% reduction in the incidence of PONV at an alpha level of 0.05 and a power of 90% using a two-sided test. To allow for exclusions and dropouts, we enrolled 291 patients in the current trial. All surgeries were performed by one of two surgeons (TKK and CBC) using the standard medial parapatellar arthrotomy with a tourniquet. A posteriorly stabilized prosthesis (Genesis II; Smith & Nephew, Memphis, TN, USA) was implanted in all patients. The patella was resurfaced, and cement fixation was used for all components in all cases. All patients received the same anesthetic and multimodal regimen to manage pain and PONV, with the exception that only the Dexa-Ra group received 10 mg intravenous dexamethasone 1 hour before surgery. One hour before surgery, multimodal oral analgesic drugs (10 mg sustained-release oxycodone, 200 mg celecoxib, 75 mg pregabalin, and 650 mg acetaminophen) were administered for preemptive analgesia on a call basis. All patients received 1.0 g cefazolin as antimicrobial prophylaxis, were premedicated using midazolam (0.03 mg/kg) before induction, and received continuous femoral nerve