Local Infiltration Analgesia Versus Quadruple Nerve Blocks in Total Knee Arthroplasty.

Local Infiltration Analgesia Versus Quadruple Nerve Blocks in Total Knee Arthroplasty: a Randomized Controlled Trial.

Total knee arthroplasty (TKA) is one of the most common orthopedic surgical procedures and is associated with severe pain in the immediate postoperative period, thus limiting early recovery.

Optimal postoperative pain management after TKA is not fully defined. While multimodal analgesia is standard, the choice of associated regional anesthesia techniques is debated.

Local infiltration analgesia (LIA) is widely used and provides effective pain relief without impairing early mobilization.

Peripheral nerve blocks have been discussed due to the risk of motor blockade, but low-concentration local anesthetics, such as 0.1% ropivacaine, allow sensory blockade while preserving motor function. Preliminary studies suggest that this concentration is effective and safe.

The main objective of this monocenter, prospective, randomized, open-label, controlled trial is to compare the analgesic efficacy of a quadruple nerve blocks (femoral, sciatic, obturator, and lateral femoral cutaneous nerves) using 0.1% ropivacaine versus standard LIA in patients undergoing TKA.

In the pre-anaesthesia room, after the implementation of classical monitoring with an oxygen mask and a peripheral venous catheter, all patients will receive an antibioprophylaxis according to the recommendations of the SFAR (French Society of Anesthesia & Intensive Care Medecine) and an injection of 10 mg of IV dexamethasone.

The surgical procedure is a total knee arthroplasty (TKA) performed under general anesthesia (GA) with a laryngeal mask. The only difference between the two groups will be the site and technique of local anesthetic (LA) injection.

The patients will be randomized into two groups:

• LIA group (usual technique): surgical local infiltration
• Quadruple nerve blocks group (experimental technique): femoral, sciatic, obturator and lateral femoral cutaneous nerve blocks

In the operating room, general anesthesia will be induced with intravenous ketamine (0.4 mg/kg) and propofol (3 mg/kg). Anesthesia will be maintained with propofol.

Other medications administered intraoperatively:

• Tranexamic acid (1 g)
• Uradipil (5 mg every 3 minutes) if systolic blood pressure (SBP) > 160 mmHg
• Norepinephrine (10 µg every 3 minutes) or Ephedrine (6 mg every 3 minutes) if SBP < 90 mmHg
• Sufentanil (initial dose of 5 µg, then 5 µg every 5 minutes as needed at the anesthesiologist's discretion)

Postoperative analgesia protocol:

• Multimodal analgesia will be instituted from the end of the surgery by the administration of paracetamol (1 g) and ketoprofen (100 mg).
• In post-anesthesia care unit (PACU): oxycodone titration if VRS (pain score) >3 according to the centre's usual care.
• In ward: systematic per os analgesia with paracetamol (1 g, 4 times a day) and ibuprofen (400 mg, 3 times a day), oxycodone (10 mg, lockout interval: 4 h) if VRS (pain score) >3 and cryotherapy.

Inclusion Criteria:

• Patients undergoing primary total knee arthroplasty under general anesthesia (laryngeal mask airway)
• Fully autonomous at home
• Planned discharge to home
• Consent for participation
• Affiliation to a social security system

Exclusion Criteria:

• Preoperative opioid use
• Chronic pain syndrome
• Valgus contraindicating sciatic nerve block
• Contraindication to any drugs used in the protocol
• Contraindication to laryngeal mask airway
• Pregnant or breastfeeding women
• Patients under protection of the adults (guardianship, curators or safeguard of justice)