This prospective randomized controlled trial aims to compare the analgesic efficacy and safety of three adjuvant strategies for ultrasound-guided Adductor Canal Block (ACB) and iPACK block in patients undergoing elective total knee arthroplasty under spinal anesthesia. All participants will receive standardized spinal anesthesia with 0.5% ropivacaine combined with ACB and iPACK blocks using 0.2% ropivacaine. Patients will be randomized into one of three groups: standard ACB + iPACK without adjuvants, ACB + iPACK with intravenous dexamethasone 8 mg, or ACB + iPACK with intravenous dexamethasone 8 mg combined with perineural dexmedetomidine added to both regional blocks.
The primary outcome will be total postoperative opioid consumption during the first 48 hours after surgery expressed as intravenous morphine equivalents. Secondary outcomes will include pain intensity at rest and during movement, duration of analgesia, time to first rescue analgesia, quadriceps muscle strength, early mobilization, adverse events, inflammatory markers, and length of hospital stay.
Age between 60 and 100 years
Scheduled for elective primary unilateral total knee arthroplasty
American Society of Anesthesiologists (ASA) physical status I-III
Ability to understand study procedures and provide written informed consent
Known allergy or hypersensitivity to ropivacaine, dexamethasone, dexmedetomidine, or any study-related medication
Contraindications to spinal anesthesia or peripheral nerve blocks
Coagulation disorders or anticoagulant therapy preventing safe regional anesthesia
Infection at the planned puncture site or systemic infection