177 patients scheduled for total knee arthroplasty were randomized to one of three groups for postoperative analgesia with an adductor canal block: continuous ACB, single-shot ACB or single-shot ACB plus intravenous dexamethasone. Patients were assessed primarily for cumulative opioid consumption, as well as pain scores, at 12, 24 and 48 hours after surgery. Results demonstrated significantly greater cumulative opioid consumption after 12 and 24 hours in the continuous ACB group compared to the single-shot ACB group. Cumulative opioid consumption was significantly greater in the continuous ACB group compared to the single-shot ACB plus IV dexamethasone group after 12 hours. Differences between groups after 48 hours were not statistically significant.