Driesman A, et al. - Among patients who underwent unilateral primary total knee arthroplasty, researchers compared the postoperative outcomes between patients who used tramadol preoperatively vs narcotics naive patients. They analyzed prospectively collected data for the participants in this retrospective study. Opiate naïve patients were 136, while 63 had received narcotics prior to the index operation; tramadol was received by 21 of those patients. A trend toward significantly less improvement in functional outcomes in the short-term postoperative period was seen in patients who received tramadol preoperatively vs opiate naïve patients.