Adductor Canal Block

For Group I, after patients are placed in the supine position, a linear ultrasound probe (13-6 MHz) will be used to identify the superficial femoral artery in the short axis, lateral to the Sartorius muscle, and anterior to the adductor magnus muscle in the adductor canal. A 22-gauge × 100 mm needle (Braun® Stimuplex) will be inserted in-plane laterally to medially under sterile conditions, and 20 mL of 0.5% bupivacaine will be injected after negative aspiration.

Adding an IPACK Block to the Adductor Canal Block

For Group II, 20 mL of 0.25% bupivacaine will be injected into the Adductor Canal after spinal anesthesia. With the knee flexed, a convex probe (3.5-6 MHz) will be placed in the popliteal region to identify the popliteal artery in the short axis. The ultrasound probe will be moved distally after the common peroneal and tibial nerves are identified. The probe will be gradually moved towards the popliteal fossa until the popliteal vessels are identified superficially. The ultrasound probe will be moved to the level where the femoral condyles merge with the femoral shaft. The popliteal artery, tibial and peroneal nerves will be visualized to identify the space between the femur and the popliteal artery. In the area known as iPACK, a 22-gauge × 100 mm needle (Braun® Stimuplex) will be inserted in-plane laterally to medially, and 20 mL of 0.25% bupivacaine will be injected after negative aspiration.