Overview
Knee arthroscopy is one of the most common orthopedic procedures, and effective postoperative analgesia is essential for early mobilization and patient comfort. Femoral nerve block provides effective analgesia after knee surgery but can cause quadriceps weakness. The anterior nerves of the knee (ANK) block is a recently described, motor-sparing fascial plane block targeting the sensory nerves of the anterior knee. This prospective, randomized, single-blind study compares ultrasound-guided ANK block with ultrasound-guided femoral nerve block in adult patients undergoing elective knee arthroscopy under spinal anesthesia, with respect to postoperative analgesic consumption, pain scores, intraoperative hemodynamics and time to first mobilization.
Description
Adult patients (18-65 years, ASA I-II) scheduled for elective knee arthroscopy under spinal anesthesia will be randomized 1:1 using sealed opaque envelopes to receive either an ultrasound-guided ANK block or an ultrasound-guided femoral nerve block in the block room before surgery. Both blocks are performed with 20 mL of 0.25% bupivacaine (10 mL of 0.5% bupivacaine diluted with 10 mL of 0.9% saline). Sensory and motor block (quadriceps strength, MRC scale) are assessed 20 minutes after the block. All patients then receive standard spinal anesthesia with 12.5 mg of 0.5% hyperbaric bupivacaine without adjuvants. Premedication is standardized (midazolam 1 mg and fentanyl 50 mcg IV). Identical dressings are applied to the groin and knee in all patients to maintain blinding.
Heart rate and blood pressure are recorded at baseline (before spinal anesthesia), skin incision, tourniquet inflation, tourniquet deflation and end of surgery. Postoperative analgesia consists of IV paracetamol and IV tramadol as rescue analgesia, administered by ward staff blinded to group allocation. Pain is assessed with a Visual Analog Scale (0-10) at rest and on movement at 0, 2, 4, 6, 12 and 24 hours postoperatively by an assessor blinded to group allocation. The anesthesiologist performing the block is not blinded. Block-related complications (local anesthetic systemic toxicity, hematoma, infection, falls/knee buckling) are recorded.
Eligibility
Inclusion Criteria:
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Inclusion Criteria:
- Age 18 to 65 years
- American Society of Anesthesiologists (ASA) physical status I-II
- Scheduled for elective knee arthroscopy
- Surgery performed under spinal anesthesia
- Written informed consent
Exclusion Criteria:
- Refusal to participate
- Allergy to local anesthetics or study analgesics
- Infection at the block site
- Coagulopathy or anticoagulant therapy
- Pre-existing neurological deficit or motor weakness in the operated limb
- Chronic pain or regular opioid use
- Inability to cooperate with pain assessment
- Emergency surgery
- Contraindication to spinal anesthesia
Exclusion Criteria:
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