Effects of Brain Beta-Amyloid on Postoperative Cognition

Inclusion Criteria: * Scheduled for total knee arthroplasty or total hip arthroplasty under general anesthesia (primary arthroplasties and revisions) * English speaking * Anticipated stay in the hospital * Not anticipated to stay intubated postoperatively * Patients who live with or have regular visits from an individual ("study partner") willing to provide information about the patient's cognitive status * Willing and able to undergo all testing procedures including neuroimaging and agree to longitudinal follow up * Adequate visual and auditory acuity to allow neuropsychological testing * Subjects with Clinical Dementia Rating Scale (CDR) of 0-0.5 * Patients who are not demented * Subjects sho signed an IRB approved informed consent prior to any study procedures Exclusion Criteria: * Clinically significant hepatic, renal, pulmonary, metabolic, or endocrine disturbances as indicated by history, which in the opinion of the investigator might pose a potential safety risk to the subject * Current clinically significant cardiovascular disease. * History of drug or alcohol abuse within the last year, or prior prolonged history of abuse * Clinically significant infections disease, including Acquired Immune Deficiency Syndrome (AIDS) or Human Immunodeficiency Virus (HIV) infection or previous positive test for hepatitis * History of relevant severe drug allergy or hypersensitivity * Received an investigational medication under an FDA IND protocol within the last 30 days. * Curren…