Adductor Canal Block With or Without Biceps Femoris Short Head Block in Total Knee Arthroplasty

Effect of Adding a Biceps Femoris Short Head Block to an Adductor Canal Block on Postoperative Pain and Functional Outcomes After Total Knee Arthroplasty: A Randomized Controlled Trial

Total knee arthroplasty is associated with moderate to severe postoperative pain, which may delay mobilization and recovery. Multimodal analgesia including regional anesthesia techniques is widely used to improve outcomes. The adductor canal block (ACB) provides anteromedial knee analgesia but may not adequately cover the posterolateral region.

The biceps femoris short head (BiFeS) block is a novel motor-sparing regional anesthesia technique targeting the posterolateral capsule of the knee. This randomized controlled trial aims to compare the analgesic efficacy and functional outcomes of ACB combined with BiFeS block versus ACB alone in patients undergoing total knee arthroplasty.

The primary outcome is posterior knee pain at postoperative 6 hours. Secondary outcomes include pain scores within 48 hours, opioid consumption, early and late functional recovery, and opioid-related adverse effects.

Study Overview

• Status: Not yet recruiting
• Conditions: Total Knee Arthroplasty
• Intervention / Treatment: Procedure: Adductor Canal Block; Procedure: Biceps Femoris Short Head Block; Procedure: Sham Biceps Femoris Short Head Block

• Study Type: Interventional
• Enrollment (Estimated): 132
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Demet Lafli Tunay, M.D.; Phone Number: +905358685831; Email: dlafli@yahoo.com

Study Locations

• Turkey (Türkiye)
  • Saricam
    • Adana, Saricam, Turkey (Türkiye), 01330
      • Çukurova University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• ASA I-III
• Adult patients undergoing unilateral primary TKA
• Planned spinal anesthesia
• Written informed consent

Exclusion Criteria:

• Coagulopathy
• Drug allergy
• BMI > 35
• Renal/hepatic failure
• Chronic pain or opioid use
• Depression or psychiatric disorder
• Revision or bilateral TKA
• Neurological deficits
• Preoperative ROM < 90°

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: ACB + BiFeS; Participants receive spinal anesthesia followed by an ultrasound-guided adductor canal block and a biceps femoris short head block using local anesthetic for postoperative analgesia.	Procedure: Adductor Canal Block; Ultrasound-guided adductor canal block performed with injection of local anesthetic into the adductor canal to block the saphenous nerve and provide postoperative analgesia following total knee arthroplasty.; Procedure: Biceps Femoris Short Head Block; Ultrasound-guided biceps femoris short head block performed with injection of local anesthetic between the biceps femoris short head and femur to target the posterolateral innervation of the knee for postoperative analgesia.
Active Comparator: ACB + sham BiFeS; Participants receive spinal anesthesia followed by an ultrasound-guided adductor canal block and a sham biceps femoris short head block using normal saline.	Procedure: Adductor Canal Block; Ultrasound-guided adductor canal block performed with injection of local anesthetic into the adductor canal to block the saphenous nerve and provide postoperative analgesia following total knee arthroplasty.; Procedure: Sham Biceps Femoris Short Head Block; Sham ultrasound-guided biceps femoris short head block performed with injection of normal saline at the same anatomical location to maintain blinding without providing active analgesia.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Posterior Knee Pain Intensity	Posterior knee pain assessed using the Numeric Rating Scale (NRS, 0-10), where 0 indicates no pain and 10 indicates worst imaginable pain.	6 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative Pain Intensity	Pain intensity at rest and during movement assessed using the Numeric Rating Scale (NRS, 0-10).	30 minutes, 1, 6, 12, 24, and 48 hours postoperatively
Total Opioid Consumption	Total opioid consumption measured from patient-controlled analgesia (PCA) device and additional opioid requirements, expressed in milligrams of morphine equivalent.	0-48 hours postoperatively
Rescue Analgesic Use	Requirement for additional analgesic medications (e.g., meperidine, paracetamol, ibuprofen) recorded as yes/no and total doses administered.	0-48 hours postoperatively
Functional Recovery	Functional recovery assessed by range of motion (ROM), quadriceps muscle strength, time to first ambulation, ability to walk 10 meters without assistance, and performance on the 5-times sit-to-stand test.	24 hours, 48 hours, and 6 weeks postoperatively
Quadriceps Muscle Strength	Quadriceps isometric muscle strength measured using a handheld dynamometer and expressed in Nm/kg.	Preoperatively, 24 hours, 48 hours, and 6 weeks postoperatively
Time to First Ambulation	Time from the end of surgery to first successful ambulation, measured in hours.	Within 48 hours postoperatively
Patient Satisfaction	Patient satisfaction with postoperative pain management assessed using a 4-point scale (excellent, good, moderate, poor).	48 hours postoperatively

Collaborators and Investigators

• Sponsor: Cukurova University

Study record dates

Study Major Dates

• Study Start (Estimated): May 15, 2026
• Primary Completion (Estimated): January 15, 2027
• Study Completion (Estimated): February 15, 2027

Study Registration Dates

• First Submitted: April 23, 2026
• First Submitted That Met QC Criteria: April 29, 2026
• First Posted (Actual): May 5, 2026

Study Record Updates

• Last Update Posted (Actual): May 5, 2026
• Last Update Submitted That Met QC Criteria: April 29, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Postoperative Pain; Total Knee Arthroplasty; Knee Osteoarthritis; Opioid Consumption; Functional Recovery; Adductor Canal Block; Biceps Femoris Short Head Block
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Musculoskeletal Diseases; Postoperative Complications; Pathologic Processes; Arthritis; Joint Diseases; Rheumatic Diseases; Osteoarthritis; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain, Postoperative; Osteoarthritis, Knee
• Other Study ID Numbers: CU-BiFeS-2026

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No