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Anterior Cruciate Ligament InjuriesNCT05754632

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

A study testing Blood Flow Restriction using Delfi Personalized Tourniquet System in people with Anterior Cruciate Ligament Injuries and Knee Injuries, run by Connecticut Children's Medical Center at 1 site in United States.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial 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. Read more about this study

Who is it for?
Ages 12 to 18 years
What is being tested?
Blood Flow Restriction using Delfi Personalized Tourniquet System
Type of treatment
Medical device
Could I receive a placebo?
No, everyone receives an active treatment
How many people
40 participants
Where
1 siteUnited States
Study dates
8 Jun 2023to 1 May 2029
Phase
Interventional
Are there results?
Not yet: the study is under way

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 12 to 18 years
  • All sexes
  • No healthy volunteers
  • Child, Adult

Who may be able to join

  • 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.

Who cannot join

  • 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).

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

United States1 site, 1 recruiting
  • Connecticut Children's Sports Physical Therapy

    Farmington, Connecticut, 06032

    Adam P Weaver, PT, DPT, 860-284-0246 ext. 79296, aweaver@connecticutchildrens.org

    Recruiting

Other trials in United States

About this study

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?

Read the detailed description

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.

Target Population Adolescent patients between the ages of 12 and 18 will be recruited at the time of surgery, specifically, those that participate in sports who are undergoing primary ACLR reconstruction at Connecticut Children's

Study Group and Control Group Inclusion Criteria

  • 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) Running, twisting, turning (racquet sports, baseball, hockey) Level II sports (1-3 days/week) Jumping, hard pivoting, cutting (basketball, volleyball, football, soccer, gymnastics, skiing. wrestling) Running, twisting, turning (racquet sports, baseball, hockey)

  • Completion of postoperative rehabilitation following standard protocols
  • Orthopedic surgical intervention and physical therapy completed at Connecticut Children's.
Being tested
Blood Flow Restriction using Delfi Personalized Tourniquet System
Keywords
physical therapy, rehabilitation
Medical subject headings
Anterior Cruciate Ligament Injuries, Knee Injuries

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Blood Flow Restriction using Delfi Personalized Tourniquet SystemDevice

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

    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.

Study groups in NCT05754632
Study groupRoleWhat they receive
BFR Intervention GroupExperimentalIn 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
Receives: Device: Blood Flow Restriction using Delfi Personalized Tourniquet System
No Intervention/Control GroupNo interventionIn 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

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. 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

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

  2. 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.

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

  3. 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.

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

  4. 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.

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

  5. 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.

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

  6. 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.

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

  7. 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.

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

  8. 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.

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

  9. 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.

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

Secondary outcomes (5)
  1. Quadriceps Hypertrophy

    Thigh Circumference measured at location 10cm superior to patella and measured in cm comparing involved to uninvolved lower extremity

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

  2. Pediatric International Knee Documentation Committee

    Patient Reported Outcome Measure- Scores range from 0 points (lowest level of function or highest level of symptoms) to 100 points (highest level of function and lowest level of symptoms).

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

  3. Knee Outcomes and Osteoarthritis Scale

    Patient Reported Outcome Measure- The score is a percentage score from 0 to 100, with 0 representing extreme problems and 100 representing no problems. This scoring direction, 100 indicating no problems

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

  4. Anterior Cruciate Ligament- Return to Sport after Injury

    Patient Reported Outcome Measure- The scores range from 0 to 100, with higher scores representing patients who are more ready to return to sport

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

  5. Tegner Activity Scale

    Tegner activity scale will measure sport level- higher level equals higher sport competitive level

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

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted6 Mar 2023
  2. Study start8 Jun 2023
  3. Primary completion1 Jun 2027 (estimated)
  4. Study completion1 May 2029 (estimated)

Resources

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
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.
Masking
None (open label)
Enrolment
40 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05754632
Sponsor's protocol ID
22-139
Status last verified
Jan 2026
First submitted
9 Feb 2023
Last updated
7 Jan 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
Yes
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing Blood Flow Restriction using Delfi Personalized Tourniquet System in people with Anterior Cruciate Ligament Injuries and Knee Injuries, run by Connecticut Children's Medical Center at 1 site in United States.

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 5 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: looking for participants now, as of the sponsor's last update on 7 Jan 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 United States. 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?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Adam P Weaver, PT, DPT (8602840296 ext. 79296, aweaver@connecticutchildrens.org), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Range of Motion (time frame: Change in range of motion at Pre-op, 3 months post-op, 6 months post-op, 9 months post-op). The study lists 9 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
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 7 Jan 2026.

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