The analgesic efficacy of the continuous adductor canal block compared to continuous intravenous fentanyl infusion with a single-shot adductor canal block in total knee arthroplasty: a randomized controlled trial

44 patients scheduled for total knee arthroplasty were randomized to a postoperative analgesia regimen including either a continuous adductor canal block or a single-shot adductor canal block followed by patient-controlled analgesia with fentanyl. Primary purpose of this study was to determine if there were any significant differences between groups in pain scores, on a numeric rating scale, over the first 48 hours after surgery. Comparison of groups demonstrated significantly lower NRS pain scores at 4 hours, 24 hours, and 48 hours in the group treated with continuous adductor canal block compared to patients treated with single-shot adductor canal block followed by PCA fentanyl.