The conventional approach to multimodal analgesia for patients presenting for total knee arthroplasty (TKA) typically includes a periarticular injection of local anesthetic with adjuvant medications. YaDeau and colleagues performed a trial hypothesizing that TKA patients undergoing spinal anesthesia with ACB, IPACK, and saline PAI would have pain scores with ambulation on postoperative day 1 that were not worse than those of patients with ACB, IPACK, and active PAI. Ninety-four patients were randomized and NRS pain with ambulation was assessed. The authors were not able to demonstrate non-inferiority of saline PAI compared to active PAI. However, there was also no significant difference in opioid consumption or pain scores between groups and this calls into question the true value of active PAI in pain outcomes after TKA. An accompanying editorial by Hussain et al elegantly interprets these findings and offers a thoughtful consideration for how future studies may better characterize the relative contribution of various regional techniques for TKA. A visual summary of their review is presented in this infographic, though the reader is strongly encouraged to review the cited article for a more thorough understanding of the illustrated concepts.

1. YaDeau JT, Cushner FD, Westrich G, et al. What is the role of a peri-articular injection for Knee Arthroplasty Patients Receiving a Multimodal Analgesia Regimen Incorporating Adductor Canal and IPACK Blocks? A Randomized Blinded Placebo-controlled Non-inferiority Trial. Anesth Analg. 2024;138:1163–1172. 2. Hussain N, et al. Regional anesthesia for knee surgery: finding positives in the negatives. Anesth Analg. 2024;138:1160–1162.