Comparing Eight Nerve Block Combinations and Local Infiltration Analgesia for Total Knee ArthroplastyNerve Block Combination May Shorten Hospital Stays After Knee Surgery

INTRODUCTION: Combining adductor canal block (ACB), infiltration between the popliteal artery and posterior capsule of the knee (IPACK), and genicular nerve blocks provides motor-sparing analgesia in total knee arthroplasty (TKA). Adding nerve blocks targeting the nerve to vastus medialis, vastus intermedius, and anterior femoral cutaneous nerve may improve postoperative pain management without affecting mobility. This study evaluated the effect of an eight-nerve block combination for pain relief after TKA versus local infiltration analgesia (LIA). METHODS: Participants were randomized into intervention or standard treatment groups. The intervention group received an eight-nerve block combination using 40 mL ropivacaine, 5 mg/mL, with 75 µg of clonidine. The control group received LIA comprising 150 mL ropivacaine, 2 mg/mL, supplemented with 0.5 mg adrenaline. The primary outcome was postoperative pain intensity, measured by the numeric rating scale (NRS) at postanesthesia care unit (PACU) arrival, 1 hour, 2 hours after PACU arrival, at ward arrival, evening of surgery, morning of postoperative day 1 (POD1), and at 14:00 POD1. Statistical analysis was performed using the Mann-Whitney U test. Secondary outcomes included 48-hour oral morphine equivalent (OME) consumption and length of hospital stay (LOS). RESULTS: A total of 217 patients scheduled for TKA were randomized. No significant differences were observed in the primary outcome. NRS at rest, presented as median (IQR), did not differ between groups at any time point. At PACU arrival 0 (0-3) vs 0 (0-4), at 1 hour 2 (0-4) vs 2 (0-5), at 2 hours 2 (0-6) vs 2.5 (0-4), at ward arrival 3 (2-5) vs 3 (2-5), on the evening of POD0 4 (3-5) vs 3.5 (2-6), on the morning of POD1 4 (3-6) vs 4 (2-5), and at 14:00 POD1 3 (2-5) vs 3 (2-5) for nerve block and LIA groups, respectively (all P > .05). Exploratory secondary outcomes indicated reduced 48-hour OME consumption presented as median (IQR), 70 mg (52.5-96.3), vs 96 mg (61.3-148.8); P = .008) and shortened hospital stay, median (IQR), 1 day (1-2), vs 2 days, (1-3); P < .001) in the nerve block group compared to the LIA group. CONCLUSIONS: No differences were observed in pain scores between the eight-nerve block combination and LIA. Secondary outcomes revealed a reduction in 48-hour opioid consumption and a modestly shorter hospital stay with nerve block compared to LIA.