To evaluate the sedative (reduces irritability or agitation), anxiolytic (reduces anxiety), and amnesic (produces temporary lack of recall) effects of propofol or midazolam when administered for preoperative medication (before administration of drugs that will put patient to sleep) in comparison to placebo. This study is to test whether the use of the pre-anesthesia medication measurably reduces anxiety in comparison to receiving no pre-anesthesia medication prior to orthopedic procedures.