Intraoperative Genicular Nerve Infiltration Offers Comparable Pain Control to Traditional Periarticular Injection After Total Knee Arthroplasty: A Randomized Controlled Trial.

Background: Postoperative pain in total knee arthroplasty (TKA) can hinder rehabilitation and impair functional outcomes. Periarticular injection (PAI) is commonly used method to mitigate postoperative pain. However, the optimal injection sites and volumes remain inconclusive. Genicular nerve infiltration (GNI), targeting 3 of the 6 primary genicular nerve branches, has shown promise in nonoperative osteoarthritis treatment. This study aimed to evaluate the efficacy of intraoperative PAI with GNI in reducing postoperative pain following TKA. Methods: This single-center, double-blinded, 3-arm randomized controlled trial enrolled 78 patients undergoing unilateral TKA (n = 26 per group). Patients were randomized to receive no injection (control), traditional PAI, or PAI with GNI targeting 3 genicular nerves. Bupivacaine was used in both injection groups. Primary outcomes included visual analog scale pain scores at rest and during motion. Secondary outcomes were opioid consumption, range of motion, modified Western Ontario and McMaster Universities Osteoarthritis scores, and adverse events. Outcomes were assessed at 24 and 48 hours and at 2 and 6 weeks postoperatively. Results: Baseline characteristics were comparable among groups. Both PAI and GNI groups had significantly better outcomes than the control group regarding pain scores at rest and motion, opioid consumption, and active knee extension at 24 and 48 hours ( Conclusions: Intraoperative GNI as part of PAI may be effective in reducing postoperative knee pain, opioid use, and improving knee extension following TKA. GNI offers a targeted, consistent, and potentially simplified alternative to conventional PAI techniques.