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

Official title

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: A Prospective, Randomized, Double-Blind, Non-Inferiority Trial

Overview

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).

Detailed description

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.

Interventions

• Procedure IPACK block
  Unilateral iPACK block with 25 mL of mixture 1:1 (0.5 % bupivacaine: 0.9% NaCl)
• Procedure BiFeS Block
  Unilateral BiFeS block with 25 mL of mixture 1:1 (0.5 % bupivacaine: 0.9% NaCl)

Primary outcome measures

• VAS Scores [Time frame: Postoperative 8th-hour]

Secondary outcome measures (3)

• VAS Scores [Time frame: Postoperative 2,4,6,12,24th-hour rest and movement]
• Total opioid consumption [Time frame: 24 hours after surgery]
• Time to first mobilization [Time frame: 24 hours after surgery]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Triple blind

Primary purpose

Treatment

Study locations

Turkey (Türkiye) · 1 center

• Soma State Hospital — Manisa

Publications

• Kilicaslan A, Tulgar S, Ahiskalioglu A, Aycan IO, Kekec AF, Arici AG, Kilic G, Sindel M. Ultrasound-guided biceps femoris short head block: a novel regional anesthesia technique for the posterolateral knee. Pain Med. 2025 Nov 1;26(11):726-732. doi: 10.1093/pm/pnaf068. PMID 40418224
• Sarikaya Ozel E, Taflan MG. Ultrasound-Guided Biceps Femoris Short Head Block for Posterolateral Knee Analgesia After Total Knee Arthroplasty: A Case Report. A A Pract. 2025 Sep 23;19(9):e02060. doi: 10.1213/XAA.0000000000002060. eCollection 2025 Sep 1. PMID 40985541
• Akesen S, Akesen B, Atici T, Gurbet A, Ermutlu C, Ozyalcin A. Comparison of efficacy between the genicular nerve block and the popliteal artery and the capsule of the posterior knee (IPACK) block for total knee replacement surgery: A prospective randomized controlled study. Acta Orthop Traumatol Turc. 2021 Mar;55(2):134-140. doi: 10.5152/j.aott.2021.20187. PMID 33847575

Identifiers

NCT: NCT07433803 · BiFeS2026

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗