160 patients undergoing total knee arthroplasty were randomized to multimodal analgesia using either a peri-articular injection (PAI) of morphine, ketorolac, ropivacaine and epinephrine, or peripheral nerve blocks (femoral and sciatic; PNB). The primary purpose of this study was to compare pain outcome between the two groups on the afternoon of the first postoperative day. Pain scores at this time point were not significantly different between groups, although pain was slightly higher in the PAI group on the day of surgery. Narcotic use on the day of surgery was also higher with PAI. However, the PAI group demonstrated shorter hospital stay and lower incidence of neurologic complications in comparison to the PNB group.