Comparison of Two Different Regional Analgesia Techniques for Patients Undergoing Total Knee Arthroplasty

The selective tibial nerve block will be performed on the popliteal crease following sterilization of the area. The probe will be placed in a transverse position at the popliteal crease to visualize the popliteal artery and the tibial nerve in short axis. A 21-gauge 50mm insulated facet tip needle (SonoPlex® STIM, Pajunk, Geisingen, DE) will be inserted in-plane with the ultrasound bean from a medial to lateral direction. Once the needle tip is adjacent to the tibial nerve, 5 ml of ropivacaine 0.75% will be injected to achieve an adequate spread of local anesthetics around the nerve.

The IPACK (Infiltration of local anesthetic between the Popliteal Artery and Capsule of the Knee) will be performed on the popliteal crease following sterilization of the area. The probe will be placed in a transverse position proximal to the popliteal crease to visualize the popliteal artery in short axis. A 21-gauge 100 mm insulated facet tip needle (SonoPlex® STIM, Pajunk, Geisingen, DE) will be inserted in-plane with the ultrasound beam, in a lateral to medial direction, between the popliteal artery and the posterior capsule, where nineteen mL of ropivacaine 0.2% will be injected under ultrasound guidance. The distribution of local anesthetics will be observed above the posterior capsule.