The Impact of Blood Flow Restriction Training in Adolescents After ACL Reconstruction: A Randomized Controlled Trial

NCT05754632 | Recruiting FDA Device

• 1 other identifier: 22-139
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

While there are a number studies that have reported on the use of blood flow restriction training (BFRT) in the adult population, there is limited information about the use of BFRT in the adolescent population. This study aims to evaluate the use of BFRT in conjunction with traditional anterior ligament reconstruction (ACLR) rehabilitation in adolescents. The purpose of this study is to compare the addition of a BFRT based exercise protocol to a standard ACL rehabilitation protocol in adolescents. Does the addition of BFRT-based exercise improve strength, hypertrophy, and patient reported outcomes after ACLR in the adolescent population?

Conditions

Anterior Cruciate Ligament Injuries; Knee Injuries; Quadriceps Muscle Atrophy

Keywords

physical therapy; rehabilitation

Outcome Measures

Primary Outcomes (9)

• Range of Motion

  Active knee range of motion: Knee AROM will be measured in supine position using a goniometer and standardized procedures reported by Norkin and White

  Change in range of motion at Pre-op, 3 months post-op, 6 months post-op, 9 months post-op

• Isometric Quad strength Peak Torque

  Isometric strength testing to measure peak torque quadriceps strength (unit: ft-lbs) as reported by isokinetic dynamometer on involved and uninvolved limb.

  Change in strength at Pre-op, 3 months post-op, 6 months post-op, 9 months post-op

• Isometric Quadriceps Strength limb symmetry index

  Quadriceps limb symmetry index is calculated by taking the values from outcome 1. \[ ( peak torque quadriceps involved limb (ft/lbs)/ peak torque quadriceps uninvolved limb (ft-lbs))\*100\] as reported by isokinetic dynamometer. This value is expressed as a percentage. 100% would equal perfect symmetry.

  Change in strength at Pre-op, 3 months post-op, 6 months post-op, 9 months post-op

• Isometric Hamstring Strength Peak Torque

  Isometric strength testing to measure peak torque hamstring strength (unit: ft-lbs) as reported by isokinetic dynamometer on involved and uninvolved limb.

  Change in strength at Pre-op, 3 months post-op, 6 months post-op, 9 months post-op

• Isometric Hamstring Strength Limb Symmetry Index

  Hamstring limb symmetry index is calculated by taking the values from outcome 3 \[ ( peak torque hamstring involved limb (ft/lbs) / peak torque hamstring uninvolved limb (ft-lbs))\*100\] as reported by isokinetic dynamometer. This value is expressed as a percentage.100% would equal perfect symmetry.

  Change in strength at Pre-op, 3 months post-op, 6 months post-op, 9 months post-op

• Isokinetic Quadriceps strength

  Isokinetic strength testing to measure peak torque quadriceps strength (unit: ft-lbs) as reported by isokinetic dynamometer on involved and uninvolved limb.

  Change in strength at 6 months and 9 months post-op

• Isokinetic Quadriceps Strength limb symmetry index

  Quadriceps limb symmetry index is calculated by taking the values from outcome 1. \[ ( peak torque quadriceps involved limb (ft/lbs)/ peak torque quadriceps uninvolved limb (ft-lbs))\*100\] as reported by isokinetic dynamometer. This value is expressed as a percentage. 100% would equal perfect symmetry.

  Change in strength at 6 months and 9 months post-op

• Isokinetic Hamstrings Strength

  Isokinetic strength testing to measure peak torque hamstring strength (unit: ft-lbs) as reported by isokinetic dynamometer on involved and uninvolved limb.

  Change in strength at 6 months and 9 months post-op

• Isokinetic Hamstring Strength limb symmetry index

  Hamstring limb symmetry index is calculated by taking the values from outcome 1. \[ ( peak torque quadriceps involved limb (ft/lbs)/ peak torque quadriceps uninvolved limb (ft-lbs))\*100\] as reported by isokinetic dynamometer. This value is expressed as a percentage. 100% would equal perfect symmetry.

  Change in strength at 6 months and 9 months post-op

Secondary Outcomes (5)

• Quadriceps Hypertrophy

  Change in strength at Pre-op, 8 weeks, 3months post-op, 6months, 9 months post-op

• Pediatric International Knee Documentation Committee

  Tracking change at Pre-op, 3months post-op, 6 months post-op, 9 months post-op. 2 years post-op

• Knee Outcomes and Osteoarthritis Scale

  Tracking change at Pre-op, 3months post-op, 6 months post-op, 9 months post-op. 2 years post-op

• Anterior Cruciate Ligament- Return to Sport after Injury

  Tracking change at Pre-op, 3months post-op, 6 months post-op, 9 months post-op. 2 years post-op

• Tegner Activity Scale

  changes from pre-operative, 9 months, and 2 years post-operative

Study Arms (2)

BFR Intervention Group

EXPERIMENTAL

In addition to the standard ACL rehabilitation protocol, the experimental group will complete 2 exercises using the Delfi BFR cuff 2x/week for 8 weeks during their treatment session at Connecticut Children's Sports Physical Therapy on the second post-operative visit. Cuff size will be determined by patient thigh circumference Limb occlusion pressure will be determined in supine position and all exercises will be completed at 80% occlusion. Long Arc Quadriceps (LAQ) progression Shuttle progression Post-op visit 2- 2 weeks Quadriceps Set Standing Straight Leg Raise 2 weeks-4 weeks Available range LAQ Standing terminal knee extension 4 weeks-8 weeks LAQ (0-90°) Single Limb Shuttle/Leg Press

Device: Blood Flow Restriction using Delfi Personalized Tourniquet System

No Intervention/Control Group

NO INTERVENTION

In addition to the standard ACL rehabilitation protocol, the control group will complete the same exercises as the experimental group starting on the second post-operative visit. Long Arc Quadriceps (LAQ) progression Shuttle progression Post-op visit 2- 2 weeks Quadriceps Set Standing Straight Leg Raise 2 weeks-4 weeks Available range LAQ Standing terminal knee extension 4 weeks-8 weeks LAQ (0-90°) Single Limb Shuttle/Leg Press

Interventions

Blood Flow Restriction using Delfi Personalized Tourniquet System DEVICE

The Delfi Tourniquet System is designed to be used in conjunction with exercise. The system automatically determines the degree of occlusion and allows for safe regulation of pressure. Patients will then complete exercises with the use of this device.

Also known as: FDA Establishment Registration Number 9681444. Device Listing Number E127474. Classification Number 878.5910. Product Code KCY. 510(k) Exempt. MID: XCDELMED1099VAN

BFR Intervention Group

Eligibility Criteria

• Age: 12 Years - 18 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Prior to surgery participated in \>50 hours/year of level I or II sports as defined by Noyes et al and planned to return to prior level.
• Level I Sports (4-7 days/week) Jumping, hard pivoting, cutting (basketball, volleyball,football, soccer, gymnastics, skiing. wrestling)
• Level II sports (1-3 days/week) Jumping, hard pivoting, cutting (basketball, volleyball,football, soccer, gymnastics, skiing. wrestling)
• Completion of postoperative rehabilitation following standard protocols
• Orthopedic surgical intervention and physical therapy completed at Connecticut Children's.

You may not qualify if:

• An additional lower extremity injury at time of knee injury or previous surgical intervention on the knee (ipsilateral and contralateral)
• Multiple ligament ruptures or trauma
• Weight bearing restrictions for greater than 4 weeks after surgery due to concomitant pathology such as meniscal root/radial repair, chondral pathology, or multi-ligament pathology
• Follow-up surgical procedures including, but not limited to, post-operative arthrofibrosis Inability to attend regular physical therapy sessions (≥80% of patient treatment sessions and all assessment visits
• Contraindications to performing BFRT including known history of central or peripheral neurologic impairments, cardiac or metabolic condition or history of deep vein thrombosis (DVT).

Sponsors & Collaborators

• Connecticut Children's Medical Center: lead
• University of Connecticut: collaborator

Study Sites (1)

Connecticut Children's Sports Physical Therapy

Farmington, Connecticut, 06032, United States

RECRUITING

MeSH Terms

Conditions

Anterior Cruciate Ligament Injuries; Knee Injuries

Condition Hierarchy (Ancestors)

Leg Injuries; Wounds and Injuries

Study Officials

• Adam Weaver, PT, DPT

  Physical Therapist

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Adam P Weaver, PT, DPT

CONTACT

8602840296; aweaver@connecticutchildrens.org

Arthur Fredericks, MSPT

CONTACT

8602840296; afredericks@connecticutchildrens.org

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: A single randomized control trial will compare the use of exercises augmented with BFRT with quantitative measurements of strength and patient-reported outcomes. A total of 40 youth and adolescent patients undergoing a surgical procedure for ACLR and subsequent physical therapy at our institution will be recruited for this study. Patients will be randomized into one of two groups using computer randomization for allocation: the intervention group receiving BFRT as part of physical therapy, and the control group will follow the institution's standard ACLR rehabilitation protocol. Both groups will follow a time- and criterion-based standardized rehabilitation protocol. The primary outcomes will be isometric and isokinetic knee peak torque and limb symmetry indices. Secondary outcomes will be quadriceps hypertrophy via mid-thigh circumference and patient-reported outcomes.

Study Record Dates

• First Submitted: February 9, 2023
• First Posted: March 6, 2023
• Study Start: June 8, 2023
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): May 1, 2029
• Last Updated: January 7, 2026

Record last verified: 2026-01

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)