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

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.

Inclusion criteria

• Patients scheduled for unilateral total knee arthroplasty
• Patients aged between 18 and 75 years
• Patients with ASA physical status I-III

Exclusion criteria

• Patients with neuropsychiatric disorders
• Patients with obesity (BMI > 30)
• Presence of local infection at the site where the block will be performed
• Patients with coagulation disorders
• Patients with uncontrolled diabetes mellitus
• Opioid dependence
• History of allergy to local anesthetic agents
• Refusal to participate in the study