Knee OsteoarthritisBiFeS-TKANCT07248072
Effect of iPACK and BiFeS Blocks on Quality of Recovery After Total Knee Arthroplasty
A study testing Adductor Canal Block (ACB) Only, IPACK block and BiFeS Block in people with Knee Osteoarthritis and Postoperative Pain Management, run by Ataturk University at 1 site in Turkey (Türkiye).
Trial summary
This prospective, randomized, double-blind clinical trial aims to compare the effects of two different posterior knee analgesia techniques-iPACK block (Interspace Between the Popliteal Artery and the Capsule of the posterior Knee) and the Biceps Femoris Short Head (BiFeS) block-when combined with an adductor canal… Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Knee Osteoarthritis, Postoperative Pain Management, Total Knee Arthroplasty
- What is being tested?
- Adductor Canal Block (ACB) Only, IPACK block and BiFeS Block
- Type of treatment
- Pill or oral medicine, Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 74 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Dec 2025to 2 Oct 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age 18-75 years
- Scheduled for elective primary unilateral total knee arthroplasty (TKA)
- Planned spinal anesthesia
- ASA physical status I-III
- Ability to understand study procedures and provide written informed consent
Who cannot join
- Known allergy or hypersensitivity to local anesthetics or other study medications
- Coagulopathy or current anticoagulant therapy
- Severe hepatic, renal, or cardiac failure
- History of neuropathic pain
- Infection at the site of proposed nerve block
- Pre-existing neuromuscular disorders in the lower extremities
- Inability to cooperate or refusal to participate in the study
- Pregnancy
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effects of iPACK and Biceps Femoris Short Head (BiFeS) Blocks Combined With Adductor Canal Block on Quality of Recovery After Total Knee Arthroplasty: A Prospective, Randomized, Double-Blind Clinical Trial
This prospective, randomized, double-blind clinical trial aims to compare the effects of two different posterior knee analgesia techniques-iPACK block (Interspace Between the Popliteal Artery and the Capsule of the posterior Knee) and the Biceps Femoris Short Head (BiFeS) block-when combined with an adductor canal block (ACB) in patients undergoing elective unilateral total knee arthroplasty (TKA). Effective postoperative analgesia is essential for early mobilization, enhanced recovery, and patient satisfaction after TKA. Although ACB provides good anterior knee analgesia while preserving quadriceps strength, additional posterior knee analgesia is often required.
The iPACK block is a commonly used technique that targets the posterior knee capsule, whereas the newer BiFeS block aims to provide more selective posterolateral sensory blockade with potentially reduced risk of motor involvement. However, comparative clinical data between these two techniques are limited.
Read more
The primary objective of this study is to evaluate the difference between the iPACK and BiFeS blocks in terms of Quality of Recovery-15 (QoR-15) scores at 24 hours postoperatively. Secondary objectives include comparisons of postoperative pain scores, opioid consumption, time to first analgesic request, quadriceps and anterior tibialis muscle strength, functional test performance, time to mobilization, active range of motion, and the incidence of adverse events.
A total of 74 adult patients scheduled for elective unilateral TKA under spinal anesthesia will be randomized in a 1:1 ratio into two groups: ACB + iPACK block or ACB + BiFeS block. All blocks will be performed under ultrasound guidance by an experienced anesthesiologist. Outcome assessments will be conducted by blinded investigators. The study aims to provide high-quality clinical evidence regarding the effectiveness of the BiFeS block compared to the widely used iPACK technique.
Read the detailed description
This study is a prospective, randomized, double-blind, parallel-group, single-center clinical trial designed to compare the effects of two posterior knee analgesia techniques-iPACK block and Biceps Femoris Short Head (BiFeS) block-when combined with an adductor canal block (ACB) on postoperative recovery outcomes following elective total knee arthroplasty (TKA). Postoperative pain after TKA is often severe and can limit early mobilization, delay rehabilitation, and negatively affect recovery. Multimodal analgesia strategies, including regional anesthesia techniques, play an essential role in optimizing postoperative outcomes.
The adductor canal block is widely used because it provides effective anterior knee analgesia while largely preserving quadriceps motor strength. However, it does not adequately address posterior knee pain. The iPACK block is frequently used to supplement ACB, providing analgesia to the posterior knee capsule by targeting the interspace between the popliteal artery and the posterior capsule. The BiFeS block is a newer regional anesthesia technique that involves injection between the femur and the short head of the biceps femoris muscle, targeting terminal sensory branches supplying the posterolateral knee. Cadaveric and early clinical data suggest that the BiFeS block may provide more selective posterior analgesia with limited spread to motor fibers, but comparative clinical data are scarce.
The primary objective of this study is to determine whether the combination of ACB + BiFeS block results in superior quality of recovery compared to ACB + iPACK block, as measured by the QoR-15 score at 24 hours postoperatively. Secondary outcomes include QoR-15 at 48 hours; pain scores at rest and during movement; total opioid consumption at 24 and 48 hours; time to first opioid request; quadriceps and anterior tibialis muscle strength; functional performance assessed using the Timed Up and Go (TUG) and Five Times Sit-to-Stand (FTSST) tests; active knee range of motion; time to first mobilization; and the incidence of adverse events such as nausea, vomiting, pruritus, sedation, neurological symptoms, local anesthetic systemic toxicity, and postoperative falls.
Eligible participants are adults aged 18-75 years undergoing elective primary unilateral TKA under spinal anesthesia, with an ASA physical status of I-III. Exclusion criteria include allergy to study medications, coagulopathy, anticoagulant therapy, severe cardiac, hepatic, or renal dysfunction, pre-existing neuropathic pain, infection at the injection site, neuromuscular disorders of the lower limb, pregnancy, or inability to cooperate with postoperative assessments. Written informed consent will be obtained from all participants. The study has received ethics approval from the Atatürk University Clinical Research Ethics Committee.
Participants will be randomized in a 1:1 ratio using computer-generated block randomization. Both patients and outcome assessors will remain blinded to group assignments. All block procedures will be performed under ultrasound guidance by an experienced anesthesiologist not involved in postoperative assessments. Standardized perioperative management will include spinal anesthesia with hyperbaric bupivacaine, perioperative non-opioid analgesics (paracetamol, dexketoprofen), antiemetic prophylaxis, and postoperative patient-controlled analgesia with fentanyl.
The sample size was calculated based on the minimal clinically important difference (MCID) for the QoR-15 score, assuming an effect size of 8 points, standard deviation of 10, power of 90%, and α = 0.05, resulting in 33 patients per group. Accounting for a 10% dropout rate, 74 patients will be enrolled.
Data will be analyzed using the intention-to-treat principle. Continuous variables will be compared with independent-samples t-tests or Mann-Whitney U tests based on distribution. Mixed-effects models will be used for repeated pain measurements. Categorical variables will be compared using chi-square or Fisher's exact tests. ANCOVA may be applied for adjusted analyses of QoR-15 outcomes.
This trial is expected to contribute important clinical evidence regarding the analgesic effectiveness, functional recovery benefits, and safety profile of the BiFeS block compared with the widely used iPACK block, helping guide postoperative analgesia strategies in total knee arthroplasty.
- Being tested
- Adductor Canal Block (ACB) Only, IPACK block, BiFeS Block
- Keywords
- Total Knee Arthroplasty, Knee Replacement, Adductor Canal Block, iPACK Block, BiFeS Block, Regional Anesthesia, Postoperative Analgesia, QoR-15, Posterior Knee Pain, Ultrasound-Guided Nerve Block
- Medical subject headings
- Osteoarthritis, Knee
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Adductor Canal Block (ACB) OnlyProcedure or surgery
Also called ACB
An ultrasound-guided adductor canal block (ACB) will be performed using 15 mL of 0.25% bupivacaine. The probe will be placed on the proximal thigh to visualize the sartorius muscle and femoral artery. The needle will be advanced in-plane into the adductor canal, and correct placement will be confirmed with 2 mL saline before injection. This block aims to provide anterior knee analgesia while preserving quadriceps strength.
IPACK blockProcedure or surgery
Also called Interspace Between the Popliteal Artery and the Capsule Block, iPACK
The iPACK block will be performed by placing the ultrasound probe at the popliteal region to visualize the popliteal artery and posterior knee capsule. A needle will be advanced in-plane, and 25 mL of 0.25% bupivacaine will be injected between the artery and posterior capsule. This block targets posterior knee pain after total knee arthroplasty without causing motor block.
BiFeS BlockProcedure or surgery
Also called Biceps Femoris Short Head Block, BiFeS
The BiFeS block will be performed with the ultrasound probe placed laterally to visualize the femur cortex and the long and short heads of the biceps femoris muscle. The needle will be advanced in-plane into the potential space between the femur and the short head of the biceps femoris. After confirming position with 2 mL saline, 25 mL of 0.25% bupivacaine will be injected. This block provides posterolateral knee analgesia with limited motor involvement.
| Study group | Role | What they receive |
|---|---|---|
| Adductor Canal Block + iPACK Block | Active comparator | Participants in this arm will receive an ultrasound-guided adductor canal block (ACB) using 15 mL of 0.25% bupivacaine, followed by an iPACK (Interspace Between the Popliteal Artery and the Capsule of the posterior Knee) block with 25 mL of 0.25% bupivacaine. Blocks will be performed under sterile ultrasound guidance by an experienced anesthesiologist who will not participate in postoperative assessments. All patients will receive standardized spinal anesthesia and perioperative analgesia. Receives: Procedure: Adductor Canal Block (ACB) Only; Procedure: IPACK block |
| Adductor Canal Block + BiFeS Block | Experimental | Participants in this arm will receive an ultrasound-guided adductor canal block (ACB) using 15 mL of 0.25% bupivacaine, followed by a BiFeS (Biceps Femoris Short Head) block performed by injecting 25 mL of 0.25% bupivacaine into the potential space between the femur and the short head of the biceps femoris muscle. Procedures will be performed under sterile ultrasound guidance by an anesthesiologist not involved in postoperative assessments. All participants will receive standardized spinal anesthesia and perioperative analgesia. Receives: Procedure: Adductor Canal Block (ACB) Only; Procedure: BiFeS Block |
What is being measured
The primary outcome is the main question the study is designed to answer.
Quality of Recovery-15 (QoR-15) Score at 24 Hours
The Quality of Recovery-15 (QoR-15) questionnaire is a validated patient-reported outcome measure assessing overall postoperative recovery across domains such as pain, physical comfort, physical independence, psychological support, and emotional well-being. The total score ranges from 0 to 150, with higher scores indicating better recovery. The outcome compares 24-hour QoR-15 scores between the ACB + iPACK group and the ACB + BiFeS group.
Measured: 24 hours postoperatively
Secondary outcomes (10)
Quality of Recovery-15 (QoR-15) Score at 48 Hours
The QoR-15 questionnaire assesses multidimensional postoperative recovery, with scores ranging from 0 to 150 (higher scores indicate better recovery). This outcome compares 48-hour QoR-15 scores between the ACB + iPACK and ACB + BiFeS groups.
Measured: 48 hours postoperatively
Pain Scores (VAS) at Rest and During Movement
Pain intensity will be evaluated using the Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst pain). Assessments will be performed at rest and during movement at predefined postoperative time points.
Measured: 2, 4, 8, 12, 24, and 48 hours postoperatively
Opioid Consumption (Fentanyl PCA)
Total fentanyl consumption will be extracted from patient-controlled analgesia (PCA) device records, including total delivered dose and number of boluses.
Measured: 24 and 48 hours postoperatively
Time to First Opioid Request
The interval between the end of surgery and the patient's first demand for opioid analgesia via PCA will be recorded, indicating the duration of effective postoperative analgesia.
Measured: Up to 48 hours postoperatively
Quadriceps and Anterior Tibialis Muscle Strength
Muscle strength will be assessed using standardized manual muscle testing (0-5 scale) for quadriceps and anterior tibialis muscles. Higher scores reflect greater strength.
Measured: 4, 8, 12, 24, and 48 hours postoperatively
Timed Up and Go (TUG) Test
Functional mobility will be evaluated using the TUG test, which measures the time required for a participant to stand from a seated position, walk 3 meters, return, and sit down. Shorter times indicate better mobility.
Measured: Postoperative Day 1 and Day 2
Five Times Sit-to-Stand Test (FTSST)
Lower extremity functional strength will be assessed by recording the time required to stand up and sit down five consecutive times. Faster performance reflects better function.
Measured: Postoperative Day 1 and Day 2
Active Range of Motion (Knee Flexion and Extension)
Knee flexion and extension will be measured using a goniometer to assess active range of motion. Higher degrees indicate improved postoperative mobility.
Measured: Postoperative Day 1 and Day 2
Time to First Mobilization
The time from arrival in the postoperative care unit to the patient's first successful mobilization (standing or walking with assistance) will be recorded.
Measured: Up to 48 hours postoperatively
Adverse Events and Complications
Adverse events including nausea, vomiting, pruritus, sedation, falls, neurological symptoms, block-related complications, and signs of local anesthetic systemic toxicity (LAST) will be monitored.
Measured: Up to 48 hours postoperatively
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Nov 2025
- Study start1 Dec 2025
- Primary completion1 Oct 2026
- Study completion2 Oct 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (10)Papers the sponsor has linked to this study.
- Other trials for Knee OsteoarthritisStudies of the same condition, open and under way.
- More trials run by Ataturk UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Two-arm, randomized, parallel-group design comparing iPACK and BiFeS blocks in combination with an adductor canal block.
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 74 participants (actual)
Sponsor and investigators
- Lead sponsor
- Ataturk University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ahmet Murat Yayik, Ataturk University
- Investigators
- Ahmet Murat Yayık, Principal Investigator, Principal investigator, Ataturk University Department of Anesthesiology and ReanimationMehmet Akif YILMAZ, assistant doctor, Study director, Ataturk University Department of Anesthesiology and Reanimation
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07248072
- Sponsor's protocol ID
- B.30.2.ATA.0.01.00/769
- Other IDs
- 2025/2
- Acronym
- BiFeS-TKA
- Status last verified
- Oct 2026
- First submitted
- 18 Nov 2025
- Last updated
- 5 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be shared because the study involves sensitive patient health information, and data confidentiality will be strictly maintained according to institutional ethical guidelines.
Publications
Kleif J, Waage J, Christensen KB, Gogenur I. Systematic review of the QoR-15 score, a patient- reported outcome measure measuring quality of recovery after surgery and anaesthesia. Br J Anaesth. 2018 Jan;120(1):28-36. doi: 10.1016/j.bja.2017.11.013. Epub 2017 Nov 22.
PubMed 29397134Kilicaslan 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.
PubMed 40418224Sarikaya 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.
PubMed 40985541Jaeger P, Zaric D, Fomsgaard JS, Hilsted KL, Bjerregaard J, Gyrn J, Mathiesen O, Larsen TK, Dahl JB. Adductor canal block versus femoral nerve block for analgesia after total knee arthroplasty: a randomized, double-blind study. Reg Anesth Pain Med. 2013 Nov-Dec;38(6):526-32. doi: 10.1097/AAP.0000000000000015.
PubMed 24121608Kehlet H, Dahl JB. Anaesthesia, surgery, and challenges in postoperative recovery. Lancet. 2003 Dec 6;362(9399):1921-8. doi: 10.1016/S0140-6736(03)14966-5.
PubMed 14667752Grosu I, Lavand'homme P, Thienpont E. Pain after knee arthroplasty: an unresolved issue. Knee Surg Sports Traumatol Arthrosc. 2014 Aug;22(8):1744-58. doi: 10.1007/s00167-013-2750-2. Epub 2013 Nov 8.
PubMed 24201900Carr AJ, Robertsson O, Graves S, Price AJ, Arden NK, Judge A, Beard DJ. Knee replacement. Lancet. 2012 Apr 7;379(9823):1331-40. doi: 10.1016/S0140-6736(11)60752-6. Epub 2012 Mar 6.
PubMed 22398175Myles PS, Myles DB, Galagher W, Chew C, MacDonald N, Dennis A. Minimal Clinically Important Difference for Three Quality of Recovery Scales. Anesthesiology. 2016 Jul;125(1):39-45. doi: 10.1097/ALN.0000000000001158.
PubMed 27159009Kertkiatkachorn W, Kampitak W, Tanavalee A, Ngarmukos S. Adductor Canal Block Combined With iPACK (Interspace Between the Popliteal Artery and the Capsule of the Posterior Knee) Block vs Periarticular Injection for Analgesia After Total Knee Arthroplasty: A Randomized Noninferiority Trial. J Arthroplasty. 2021 Jan;36(1):122-129.e1. doi: 10.1016/j.arth.2020.06.086. Epub 2020 Jul 2.
PubMed 32694032Abdullah MA, Abu Elyazed MM, Mostafa SF. The Interspace Between Popliteal Artery and Posterior Capsule of the Knee (IPACK) Block in Knee Arthroplasty: A Prospective Randomized Trial. Pain Physician. 2022 May;25(3):E427-E433.
PubMed 35652772
Study at a glance
From the registry record, last updated by the sponsor on 5 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of iPACK and Biceps Femoris Short Head (BiFeS) Blocks Combined With Adductor Canal Block on Quality of Recovery After Total Knee Arthroplasty: A Prospective, Randomized, Double-Blind Clinical Trial
- ClinicalTrials.gov ID
- NCT07248072
- Acronym / sponsor ID
- BiFeS-TKA / B.30.2.ATA.0.01.00/769
- Keywords
- Total Knee Arthroplasty, Knee Replacement, Adductor Canal Block, iPACK Block, BiFeS Block, Regional Anesthesia, Postoperative Analgesia, QoR-15
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 74 participants (actual)
- Lead sponsor
- Ataturk UniversityUniversity, hospital or other
- Study start
- 1 Dec 2025 (actual)
- Primary completion
- 1 Oct 2026 (actual)
- Study completion
- 2 Oct 2026 (actual)
- First posted
- 25 Nov 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This prospective, randomized, double-blind clinical trial aims to compare the effects of two different posterior knee analgesia techniques-iPACK block (Interspace Between the Popliteal Artery and the Capsule of the posterior Knee) and the Biceps Femoris Short Head (BiFeS) block-when combined with an adductor canal block (ACB) in patients undergoing elective unilateral total knee arthroplasty (TKA). Effective postoperative analgesia is essential for early mobilization, enhanced recovery, and patient satisfaction after TKA. Although ACB provides good anterior knee analgesia while preserving quadriceps strength, additional posterior knee analgesia is often required.
The iPACK block is a commonly used technique that targets the posterior knee capsule, whereas the newer BiFeS block aims to provide more selective posterolateral sensory blockade with potentially reduced risk of motor involvement. However, comparative clinical data between these two techniques are limited.
The primary objective of this study is to evaluate the difference between the iPACK and BiFeS blocks in terms of Quality of Recovery-15 (QoR-15) scores at 24 hours postoperatively. Secondary objectives include comparisons of postoperative pain scores, opioid consumption, time to first analgesic request, quadriceps and anterior tibialis muscle strength, functional test performance, time to mobilization, active range of motion, and the incidence of adverse events.
A total of 74 adult patients scheduled for elective unilateral TKA under spinal anesthesia will be randomized in a 1:1 ratio into two groups: ACB + iPACK block or ACB + BiFeS block. All blocks will be performed under ultrasound guidance by an experienced anesthesiologist. Outcome assessments will be conducted by blinded investigators. The study aims to provide high-quality clinical evidence regarding the effectiveness of the BiFeS block compared to the widely used iPACK technique.
Detailed description
This study is a prospective, randomized, double-blind, parallel-group, single-center clinical trial designed to compare the effects of two posterior knee analgesia techniques-iPACK block and Biceps Femoris Short Head (BiFeS) block-when combined with an adductor canal block (ACB) on postoperative recovery outcomes following elective total knee arthroplasty (TKA). Postoperative pain after TKA is often severe and can limit early mobilization, delay rehabilitation, and negatively affect recovery. Multimodal analgesia strategies, including regional anesthesia techniques, play an essential role in optimizing postoperative outcomes.
The adductor canal block is widely used because it provides effective anterior knee analgesia while largely preserving quadriceps motor strength. However, it does not adequately address posterior knee pain. The iPACK block is frequently used to supplement ACB, providing analgesia to the posterior knee capsule by targeting the interspace between the popliteal artery and the posterior capsule. The BiFeS block is a newer regional anesthesia technique that involves injection between the femur and the short head of the biceps femoris muscle, targeting terminal sensory branches supplying the posterolateral knee. Cadaveric and early clinical data suggest that the BiFeS block may provide more selective posterior analgesia with limited spread to motor fibers, but comparative clinical data are scarce.
The primary objective of this study is to determine whether the combination of ACB + BiFeS block results in superior quality of recovery compared to ACB + iPACK block, as measured by the QoR-15 score at 24 hours postoperatively. Secondary outcomes include QoR-15 at 48 hours; pain scores at rest and during movement; total opioid consumption at 24 and 48 hours; time to first opioid request; quadriceps and anterior tibialis muscle strength; functional performance assessed using the Timed Up and Go (TUG) and Five Times Sit-to-Stand (FTSST) tests; active knee range of motion; time to first mobilization; and the incidence of adverse events such as nausea, vomiting, pruritus, sedation, neurological symptoms, local anesthetic systemic toxicity, and postoperative falls.
Eligible participants are adults aged 18-75 years undergoing elective primary unilateral TKA under spinal anesthesia, with an ASA physical status of I-III. Exclusion criteria include allergy to study medications, coagulopathy, anticoagulant therapy, severe cardiac, hepatic, or renal dysfunction, pre-existing neuropathic pain, infection at the injection site, neuromuscular disorders of the lower limb, pregnancy, or inability to cooperate with postoperative assessments. Written informed consent will be obtained from all participants. The study has received ethics approval from the Atatürk University Clinical Research Ethics Committee.
Participants will be randomized in a 1:1 ratio using computer-generated block randomization. Both patients and outcome assessors will remain blinded to group assignments. All block procedures will be performed under ultrasound guidance by an experienced anesthesiologist not involved in postoperative assessments. Standardized perioperative management will include spinal anesthesia with hyperbaric bupivacaine, perioperative non-opioid analgesics (paracetamol, dexketoprofen), antiemetic prophylaxis, and postoperative patient-controlled analgesia with fentanyl.
The sample size was calculated based on the minimal clinically important difference (MCID) for the QoR-15 score, assuming an effect size of 8 points, standard deviation of 10, power of 90%, and α = 0.05, resulting in 33 patients per group. Accounting for a 10% dropout rate, 74 patients will be enrolled.
Data will be analyzed using the intention-to-treat principle. Continuous variables will be compared with independent-samples t-tests or Mann-Whitney U tests based on distribution. Mixed-effects models will be used for repeated pain measurements. Categorical variables will be compared using chi-square or Fisher's exact tests. ANCOVA may be applied for adjusted analyses of QoR-15 outcomes.
This trial is expected to contribute important clinical evidence regarding the analgesic effectiveness, functional recovery benefits, and safety profile of the BiFeS block compared with the widely used iPACK block, helping guide postoperative analgesia strategies in total knee arthroplasty.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- Two-arm, randomized, parallel-group design comparing iPACK and BiFeS blocks in combination with an adductor canal block.
| Arm | Type | Receives |
|---|---|---|
| Adductor Canal Block + iPACK Block | Active comparator | Procedure: Adductor Canal Block (ACB) Only, Procedure: IPACK blockParticipants in this arm will receive an ultrasound-guided adductor canal block (ACB) using 15 mL of 0.25% bupivacaine, followed by an iPACK (Interspace Between the Popliteal Artery and the Capsule of the posterior Knee) block with 25 mL of 0.25% bupivacaine. Blocks will be performed under sterile ultrasound guidance by an experienced anesthesiologist who will not participate in postoperative assessments. All patients will receive standardized spinal anesthesia and perioperative analgesia. |
| Adductor Canal Block + BiFeS Block | Experimental | Procedure: Adductor Canal Block (ACB) Only, Procedure: BiFeS BlockParticipants in this arm will receive an ultrasound-guided adductor canal block (ACB) using 15 mL of 0.25% bupivacaine, followed by a BiFeS (Biceps Femoris Short Head) block performed by injecting 25 mL of 0.25% bupivacaine into the potential space between the femur and the short head of the biceps femoris muscle. Procedures will be performed under sterile ultrasound guidance by an anesthesiologist not involved in postoperative assessments. All participants will receive standardized spinal anesthesia and perioperative analgesia. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age 18-75 years
- Scheduled for elective primary unilateral total knee arthroplasty (TKA)
- Planned spinal anesthesia
- ASA physical status I-III
- Ability to understand study procedures and provide written informed consent
Key exclusion criteria (8 listed)
- Known allergy or hypersensitivity to local anesthetics or other study medications
- Coagulopathy or current anticoagulant therapy
- Severe hepatic, renal, or cardiac failure
- History of neuropathic pain
- Infection at the site of proposed nerve block
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Adductor Canal Block (ACB) OnlyAlso: ACBAn ultrasound-guided adductor canal block (ACB) will be performed using 15 mL of 0.25% bupivacaine. The probe will be placed on the proximal thigh to visualize the sartorius muscle and femoral artery. The needle will be advanced in-plane into the adductor canal, and correct placement will be confirmed with 2 mL saline before injection. This block aims to provide anterior knee analgesia while preserving quadriceps strength. | Procedure or surgery | Adductor Canal Block + BiFeS Block, Adductor Canal Block + iPACK Block |
| IPACK blockAlso: Interspace Between the Popliteal Artery and the Capsule Block, iPACKThe iPACK block will be performed by placing the ultrasound probe at the popliteal region to visualize the popliteal artery and posterior knee capsule. A needle will be advanced in-plane, and 25 mL of 0.25% bupivacaine will be injected between the artery and posterior capsule. This block targets posterior knee pain after total knee arthroplasty without causing motor block. | Procedure or surgery | Adductor Canal Block + iPACK Block |
| BiFeS BlockAlso: Biceps Femoris Short Head Block, BiFeSThe BiFeS block will be performed with the ultrasound probe placed laterally to visualize the femur cortex and the long and short heads of the biceps femoris muscle. The needle will be advanced in-plane into the potential space between the femur and the short head of the biceps femoris. After confirming position with 2 mL saline, 25 mL of 0.25% bupivacaine will be injected. This block provides posterolateral knee analgesia with limited motor involvement. | Procedure or surgery | Adductor Canal Block + BiFeS Block |
Primary outcome
Quality of Recovery-15 (QoR-15) Score at 24 Hours
Time frame: 24 hours postoperatively
The Quality of Recovery-15 (QoR-15) questionnaire is a validated patient-reported outcome measure assessing overall postoperative recovery across domains such as pain, physical comfort, physical independence, psychological support, and emotional well-being. The total score ranges from 0 to 150, with higher scores indicating better recovery. The outcome compares 24-hour QoR-15 scores between the ACB + iPACK group and the ACB + BiFeS group.
10 secondary outcomes
Quality of Recovery-15 (QoR-15) Score at 48 Hours
Time frame: 48 hours postoperatively
Pain Scores (VAS) at Rest and During Movement
Time frame: 2, 4, 8, 12, 24, and 48 hours postoperatively
Opioid Consumption (Fentanyl PCA)
Time frame: 24 and 48 hours postoperatively
Time to First Opioid Request
Time frame: Up to 48 hours postoperatively
Quadriceps and Anterior Tibialis Muscle Strength
Time frame: 4, 8, 12, 24, and 48 hours postoperatively
Timed Up and Go (TUG) Test
Time frame: Postoperative Day 1 and Day 2
Five Times Sit-to-Stand Test (FTSST)
Time frame: Postoperative Day 1 and Day 2
Active Range of Motion (Knee Flexion and Extension)
Time frame: Postoperative Day 1 and Day 2
Time to First Mobilization
Time frame: Up to 48 hours postoperatively
Adverse Events and Complications
Time frame: Up to 48 hours postoperatively
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Oct 2026.
- Background: PubMed 29397134Kleif J, Waage J, Christensen KB, Gogenur I. Systematic review of the QoR-15 score, a patient- reported outcome measure measuring quality of recovery after surgery and anaesthesia. Br J Anaesth. 2018 Jan;120(1):28-36. doi: 10.1016/j.bja.2017.11.013. Epub 2017 Nov 22.
- Background: PubMed 40418224Kilicaslan 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.
- Background: PubMed 40985541Sarikaya 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.
- Background: PubMed 24121608Jaeger P, Zaric D, Fomsgaard JS, Hilsted KL, Bjerregaard J, Gyrn J, Mathiesen O, Larsen TK, Dahl JB. Adductor canal block versus femoral nerve block for analgesia after total knee arthroplasty: a randomized, double-blind study. Reg Anesth Pain Med. 2013 Nov-Dec;38(6):526-32. doi: 10.1097/AAP.0000000000000015.
- Background: PubMed 14667752Kehlet H, Dahl JB. Anaesthesia, surgery, and challenges in postoperative recovery. Lancet. 2003 Dec 6;362(9399):1921-8. doi: 10.1016/S0140-6736(03)14966-5.
- Background: PubMed 24201900Grosu I, Lavand'homme P, Thienpont E. Pain after knee arthroplasty: an unresolved issue. Knee Surg Sports Traumatol Arthrosc. 2014 Aug;22(8):1744-58. doi: 10.1007/s00167-013-2750-2. Epub 2013 Nov 8.
- Background: PubMed 22398175Carr AJ, Robertsson O, Graves S, Price AJ, Arden NK, Judge A, Beard DJ. Knee replacement. Lancet. 2012 Apr 7;379(9823):1331-40. doi: 10.1016/S0140-6736(11)60752-6. Epub 2012 Mar 6.
- Results publication: PubMed 27159009Myles PS, Myles DB, Galagher W, Chew C, MacDonald N, Dennis A. Minimal Clinically Important Difference for Three Quality of Recovery Scales. Anesthesiology. 2016 Jul;125(1):39-45. doi: 10.1097/ALN.0000000000001158.
- Results publication: PubMed 32694032Kertkiatkachorn W, Kampitak W, Tanavalee A, Ngarmukos S. Adductor Canal Block Combined With iPACK (Interspace Between the Popliteal Artery and the Capsule of the Posterior Knee) Block vs Periarticular Injection for Analgesia After Total Knee Arthroplasty: A Randomized Noninferiority Trial. J Arthroplasty. 2021 Jan;36(1):122-129.e1. doi: 10.1016/j.arth.2020.06.086. Epub 2020 Jul 2.
- Results publication: PubMed 35652772Abdullah MA, Abu Elyazed MM, Mostafa SF. The Interspace Between Popliteal Artery and Posterior Capsule of the Knee (IPACK) Block in Knee Arthroplasty: A Prospective Randomized Trial. Pain Physician. 2022 May;25(3):E427-E433.
- Individual participant dataSharing planned: No. Individual participant data (IPD) will not be shared because the study involves sensitive patient health information, and data confidentiality will be strictly maintained according to institutional ethical guidelines.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Ahmet Murat Yayık, Principal Investigator principal investigator
Ataturk University Department of Anesthesiology and Reanimation
Mehmet Akif YILMAZ, assistant doctor study director
Ataturk University Department of Anesthesiology and Reanimation
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Adductor Canal Block (ACB) Only, IPACK block and BiFeS Block in people with Knee Osteoarthritis and Postoperative Pain Management, run by Ataturk University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Quality of Recovery-15 (QoR-15) Score at 24 Hours (time frame: 24 hours postoperatively). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07248072, which also lists 10 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Oct 2026.