{
  "abstract": "Background Both popliteal plexus block and infiltration between the popliteal artery and capsule of the posterior knee (IPACK) block can alleviate posterior knee pain after total knee arthroplasty (TKA) while preserving motor function. We aimed to assess whether popliteal plexus block is non-inferior to IPACK block in reducing posterior knee pain after TKA.Methods Eighty-six participants undergoing elective TKA were randomized to receive popliteal plexus block or IPACK block combined with femoral triangle block. The primary outcome was moderate-to-severe posterior knee pain at eight postoperative hours. Secondary outcomes included pain scores, fentanyl consumption, sensorimotor function, range of motion, block performance time, quality of recovery, and participant satisfaction. Injectate spread in popliteal plexus block was also assessed in seven cadaveric legs.Results The lower bound of the 90% CI for the between-group difference (IPACK – popliteal plexus block) in moderate-to-severe posterior knee pain did not exceed the 17% non-inferiority margin (difference=4.7, (90% CI −5.6 to 14.9; p<0.001)), demonstrating that popliteal plexus block was non-inferior to IPACK block. The block performance time (median (IQR)) was significantly shorter in the popliteal plexus block group (3 (3–5) min) than in the IPACK group (5 (5–6) min; p<0.0001). No significant difference in the preservation of motor function was observed. The posterior articular branches were stained in all the cadaveric specimens.Conclusions Compared with the IPACK block, popliteal plexus block provides non-inferior posterior knee analgesia following TKA while maintaining ankle muscle strength, with the additional advantage of having a shorter block performance time.Trial registration number UMIN000052472; URL: https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000059848.",
  "authors": [
    {
      "affiliations": [
        "Department of Anesthesiology and Pain Medicine, Juntendo University School of Medicine, Tokyo, Japan"
      ],
      "name": "Takashi Fujino"
    },
    {
      "affiliations": [
        "Department of Anesthesiology and Pain Medicine, Juntendo University School of Medicine, Tokyo, Japan"
      ],
      "name": "Keiko Taga"
    },
    {
      "affiliations": [
        "Department of Anesthesiology and Pain Medicine, Juntendo University School of Medicine, Tokyo, Japan"
      ],
      "name": "Masahiko Odo"
    },
    {
      "affiliations": [
        "Department of Physical Therapy, Faculty of Health Science, Juntendo University, Tokyo, Japan"
      ],
      "name": "Hidaka Anetai"
    },
    {
      "affiliations": [
        "Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo, Japan"
      ],
      "name": "Haruka Kaneko"
    },
    {
      "affiliations": [
        "Medical Technology Innovation Center, Juntendo University, Tokyo, Japan"
      ],
      "name": "Saki Uchiyama"
    },
    {
      "affiliations": [
        "Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo, Japan"
      ],
      "name": "Mitsuaki Kubota"
    },
    {
      "affiliations": [
        "Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo, Japan"
      ],
      "name": "Yoshitomo Saita"
    },
    {
      "affiliations": [
        "Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo, Japan"
      ],
      "name": "Keiichi Yoshida"
    },
    {
      "affiliations": [
        "Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo, Japan"
      ],
      "name": "Shinnosuke Hada"
    },
    {
      "affiliations": [
        "Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo, Japan"
      ],
      "name": "Youngji Kim"
    },
    {
      "affiliations": [
        "Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo, Japan"
      ],
      "name": "Jun Shiozawa"
    },
    {
      "affiliations": [
        "Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan"
      ],
      "name": "Koichiro Ichimura"
    },
    {
      "affiliations": [
        "Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo, Japan"
      ],
      "name": "Muneaki Ishijima"
    },
    {
      "affiliations": [
        "Department of Anesthesiology and Pain Medicine, Juntendo University School of Medicine, Tokyo, Japan"
      ],
      "name": "Izumi Kawagoe"
    }
  ],
  "title": "Analgesic efficacy of popliteal plexus block versus infiltration between the popliteal artery and capsule of the posterior knee block combined with femoral triangle block after total knee arthroplasty: a randomized non-inferiority trial and cadaveric evaluation",
  "uid": "bc0d8cd6-9f2b-5aed-881e-392c95c9a6f6"
}