Comparison of the Postoperative Analgesic Efficacy of Infiltration Between the Popliteal Artery and the Capsule of the Knee (iPACK) Block and the Biceps Femoris Short Head Plane (BiFeS) Block in Total Knee Arthroplasty

This study aims to compare the effects of two regional analgesia techniques applied in patients undergoing unilateral total knee arthroplasty-Infiltration between the Popliteal Artery and the Capsule of the Knee (iPACK) block and the Biceps Femoris Short Head Plane (BiFeS) block-on ease of application, postoperative pain scores, time to mobilization, total postoperative opioid consumption, need for first rescue analgesia, and the incidence of nausea-vomiting and pruritus.All patients will be followed postoperatively according to a standard pain management protocol, and pain assessments will be performed at predetermined time intervals using the VAS (Visual Analog Scale).

Total knee arthroplasty is one of the most commonly performed orthopedic procedures. Patients experience significant pain in the postoperative period. This pain delays recovery, prolongs the time to mobilization, and increases the length of hospital stay. Currently, multimodal analgesia techniques are used for postoperative pain management. These methods include systemic opioids, epidural analgesia, lumbar plexus block, femoral block, adductor canal block, iPACK block, and the newly defined and proven effective BiFeS block. In recent years, the adductor canal block has been frequently preferred because it is applied more distally and does not cause motor blockade. It primarily provides analgesia to the anteromedial aspect of the knee. The iPACK block and the BiFeS block can be used as complementary techniques to the adductor canal block, as they also affect the nerves responsible for the posterolateral innervation of the knee. Since they do not produce motor blockade, they are thought to contribute to early postoperative mobilization. During the iPACK block, local anesthetic is infiltrated between the posterior capsule of the knee and the popliteal artery. It has also been shown that a superior lateral genicular nerve block should be added to this block. The BiFeS block is performed with the patient in the supine position by infiltrating local anesthetic between the short head of the biceps femoris muscle and the lateral femoral condyle at a more proximal level. Due to its distance from the surgical site, the risk of infection is lower. In this study, the investigators aimed to compare the ease of application and the roles of these blocks-routinely performed at our center as part of multimodal analgesia-in providing effective postoperative analgesia.