Comparing ACB+IPACK and ACB+BiFeS Block Combinations for Analgesia in Total Knee Arthroplasty

Total knee arthroplasty (TKA) is associated with severe postoperative pain that delays mobilization, prolongs hospital stay, and reduces patient satisfaction. Regional analgesia techniques have gained prominence due to their opioid-sparing effects and favorable complication profiles compared to general anesthesia. While adductor canal block (ACB) effectively manages anterior knee pain with preserved motor function, posterior knee pain remains a challenge. IPACK (Infiltration between the Popliteal Artery and Capsule of the Knee) and the Biceps Femoris Short Head (BiFeS) block are techniques targeting posterior capsule innervation without causing motor block.This prospective study aims to compare the postoperative analgesic efficacy of ultrasound-guided ACB+IPACK versus ACB+BiFeS block combinations in patients undergoing TKA under spinal anesthesia. Patients (ASA I-III, age 18-80, BMI ≤35) will be randomized into two groups (n=39 each). Primary outcomes include NRS pain scores at rest and on movement, and opioid consumption at 0, 1, 3, 6, 12, 18, and 24 hours postoperatively. Secondary outcomes include time to first mobilization, motor block incidence, quadriceps muscle strength assessment, PONV, and quality of recovery (QoR-15).