Effects of Perioperative Intravenous Dexamethasone on the Severity of Persistent Postsurgical Pain After Total Knee Arthroplasty : A Prospective, Randomized, Double-blind, Placebo-controlled Trial

Inclusion Criteria: * Age \> 40 years (45) * Primary knee osteoarthritis diagnosed using the American College of Rheumatology criteria (46) * Undergoing elective, primary and unilateral total knee arthroplasty * American Society of Anesthesiology (ASA) physical status class 1-3 * BMI \< 40 kg/m2 Exclusion Criteria: * History of active rheumatic diseases * History of previous musculoskeletal injury of the same knee for excluding patients with secondary knee osteoarthritis * History of previous surgery on the same knee * History of adverse effects from medications to be used in this study * Contraindication to spinal anesthesia * History of psychiatric disorders or cognitive impairment * Contraindication to corticosteroid agents * Poorly controlled diabetes mellitus (HbA1C \> 7.5) * Poorly controlled hypertension * History of ischemic heart disease or peripheral arterial disease or cerebrovascular disease * Hepatic insufficiency (Child-Pugh score \> 5) * Renal insufficiency (Creatinine clearance \< 30 mL/min) * History of cataracts or glaucoma or ocular hypertension * History of steroid or immunosuppressive drug use within 6 months of surgery