Reducing Perioperative Oxidative Stress to Prevent Postoperative Chronic Pain Following Total Knee Arthroplasty

Inclusion Criteria: * Age 50 or older * Intact cognitive status and ability to provide informed consent (based on cognitive screening with the Mini Mental State Examination) * Ability to read and write in English sufficiently to understand and complete study questionnaires * Undergoing unilateral primary TKA * Medical diagnosis of osteoarthritis * Past 24 hour worst numeric rating scale (NRS) pain of at least 4/10. Exclusion Criteria: * Diagnosis of pre-existing neuropathy * Untreated hypo/hyperthyroidism * Untreated heart disease * Alanine transaminase/aspartate transaminase \>2x upper-limit of normal range * serum creatinine \>1.5 mg/dl * Pregnancy * Complex Regional Pain Syndrome (CRPS) diagnosis prior to undergoing TKA * Presence of lower extremity vascular disease, inflammatory or autoimmune disorders, or malignancy * Presence of current clinically significant chronic pain conditions outside of the lower extremity ( daily pain for \>3 months and greater ≥3/10 in intensity or the focus of medical care) * Presence of other medical conditions that in the opinion of the orthopedic surgeon co-investigators would make a patient's study participation unsafe