Blood Flow Restriction Training for ACL Reconstruction Recovery

Overseen By Arthur Fredericks, MSPT

Age: < 65

Sex: Any

Trial Phase: Academic

Sponsor: Connecticut Children's Medical Center

Disqualifiers: Lower extremity injury, Multiple ligament ruptures, Weight bearing restrictions, Neurologic impairments, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Approved in 3 Jurisdictions This treatment is already approved in other countries

Compensation: Varies

Number of Visits: 5

Duration: 8 weeks

40 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial explores whether adding blood flow restriction training (BFRT) to regular rehab can improve recovery for teens after ACL surgery. BFRT uses a special cuff to limit blood flow during exercise, potentially boosting strength and muscle growth. The trial will compare two groups: one doing standard rehab and the other incorporating BFRT exercises with the Delfi Personalized Tourniquet System. Teens who played sports like basketball or soccer before their ACL surgery and plan to return are well-suited for this study. As an unphased trial, this study offers a unique opportunity to potentially enhance recovery and facilitate a more effective return to sports.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What prior data suggests that this blood flow restriction training protocol is safe for adolescents?

Research shows that blood flow restriction training (BFRT) is generally well-tolerated in adults. A review of studies found that BFRT can aid muscle recovery, such as preventing muscle shrinkage, after ACL surgery. The Delfi Personalized Tourniquet System, used for BFRT, safely controls pressure during exercises, enhancing treatment safety.

While less information exists about BFRT in teenagers, the equipment is designed to ensure a safe experience. Studies with adults have reported no serious adverse reactions, suggesting that, with careful use, BFRT could be safe for teens as well. However, since this trial explores BFRT in teens, monitoring for any new findings is crucial. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about blood flow restriction (BFR) training for ACL reconstruction recovery because it adds a novel twist to standard rehab exercises. Traditional ACL recovery relies on physical therapy exercises to rebuild strength, but BFR training enhances this by using the Delfi Personalized Tourniquet System. This system safely reduces blood flow to the muscles during exercise, creating a kind of "low-oxygen" workout that can boost muscle growth and strength more effectively, even at lower exercise intensities. This approach could potentially accelerate recovery times and improve outcomes for patients compared to standard rehabilitation methods.

What evidence suggests that the Delfi Personalized Tourniquet System is effective for ACL reconstruction recovery in adolescents?

Research shows that blood flow restriction training (BFRT) can aid recovery after ACL (anterior cruciate ligament) surgery. BFRT uses a cuff to gently limit blood flow during exercise, increasing strength and muscle size. Studies have found it reduces muscle loss and boosts muscle strength more effectively than standard rehab alone. In this trial, participants in the BFR Intervention Group will use the Delfi Personalized Tourniquet System, which safely controls pressure during BFRT, making it a promising rehabilitation option. Meanwhile, the Control Group will follow the standard ACL rehabilitation protocol without BFRT. In top athletes, BFRT has improved strength but did not speed up their return to sports. ^{1 2 3 4 6}

Who Is on the Research Team?

Adam Weaver, PT, DPT

Principal Investigator

Physical Therapist

Are You a Good Fit for This Trial?

This trial is for adolescents who have had ACL reconstruction and were active in sports before their injury. They must have completed surgery and physical therapy at Connecticut Children's, following standard protocols, without other major knee injuries or surgeries, weight bearing restrictions over 4 weeks due to additional pathology, or follow-up procedures like arthrofibrosis.

Inclusion Criteria

Before surgery, you participated in more than 50 hours per year of intense sports and plan to go back to that level after the surgery.

I completed orthopedic surgery and physical therapy at Connecticut Children's.

I have finished my post-surgery rehab according to the standard plan.

Exclusion Criteria

I cannot attend most of my physical therapy sessions.

I must limit putting weight on my leg for over 4 weeks after surgery due to other knee issues.

I have another leg injury or had surgery on either knee.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants undergo ACL reconstruction surgery followed by a rehabilitation protocol, with the experimental group receiving additional blood flow restriction training (BFRT) exercises.

8 weeks

2 visits per week (in-person)

Follow-up

Participants are monitored for changes in strength, hypertrophy, and patient-reported outcomes at various intervals post-operation.

2 years

Regular follow-up visits at 3, 6, 9 months, and 2 years post-op

What Are the Treatments Tested in This Trial?

Interventions

• Delfi Personalized Tourniquet System

Trial Overview The study tests if adding Blood Flow Restriction Training (BFRT) using the Delfi Personalized Tourniquet System to standard ACL rehab improves strength, muscle growth, and patient outcomes in adolescents after ACL reconstruction compared to just the standard rehab protocol.

How Is the Trial Designed?

Group I: BFR Intervention Group Experimental Treatment 1 Intervention

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

Group II: No Intervention/Control Group Active Control 1 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

Who Is Running the Clinical Trial?

Connecticut Children's Medical Center

Lead Sponsor

Trials

76

Recruited

30,000+

University of Connecticut

Collaborator

Trials

194

Recruited

162,000+

Published Research Related to This Trial

Blood flow restriction (BFR) training combined with low-intensity resistance training (LIRT) shows promise in reducing quadriceps muscle atrophy after ACL reconstruction, with three out of four studies indicating an increase in muscle cross-sectional area.

The systematic review assessed four studies with moderate strength, suggesting that while BFR may be beneficial, further research is needed before it can be widely recommended in clinical practice.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A SYSTEMATIC REVIEW OF THE EFFECTS OF BLOOD FLOW RESTRICTION TRAINING ON QUADRICEPS MUSCLE ATROPHY AND CIRCUMFERENCE POST ACL RECONSTRUCTION. Charles, D., White, R., Reyes, C., et al.[2022]

In a study of 46 subjects over 8 weeks, both blood flow restriction (BFR) training and traditional exercise led to significant strength gains in the rotator cuff muscles, but there was no difference in strength improvements between the two methods.

Both groups also experienced increases in supraspinatus tendon thickness, indicating that low-load, high-repetition exercises can effectively enhance rotator cuff strength and tendon size, regardless of BFR application.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Blood Flow Restriction Training for the Rotator Cuff: A Randomized Controlled Trial. Brumitt, J., Hutchison, MK., Kang, D., et al.[2023]

In a study of 29 participants, a minimum blood flow restriction pressure of 50% limb occlusion pressure (LOP) was necessary to significantly reduce arterial blood flow in the lower limbs, indicating a threshold for effective blood flow restriction.

The study found no significant differences in vessel diameter or blood flow at higher occlusion pressures (60% to 90% LOP), suggesting that pressures above 50% LOP may not provide additional benefits for blood flow restriction during exercise.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Acute Blood Flow Responses to Varying Blood Flow Restriction Pressures in the Lower Limb. Hornikel, B., Saffold, KS., Mota, JA., et al.[2023]

This study will evaluate the effectiveness of blood flow restriction training (BFRT) on improving quadriceps strength and knee biomechanics in 60 participants aged 15 to 40 with ACL tears, using a randomized, double-blind, placebo-controlled design.

If successful, BFRT could provide a targeted intervention to address long-lasting quadriceps strength deficits after ACL reconstruction, potentially leading to better recovery outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Effect of Blood Flow Restriction Training on Quadriceps Muscle Strength, Morphology, Physiology, and Knee Biomechanics Before and After Anterior Cruciate Ligament Reconstruction: Protocol for a Randomized Clinical Trial. Erickson, LN., Lucas, KCH., Davis, KA., et al.[2020]

In a study comparing 67 rheumatoid arthritis patients using a tapering strategy for TNF inhibitors to 77 patients on a standard regimen, both groups maintained similar disease activity scores (DAS28) after one year, indicating effective disease control.

The tapering group experienced significant reductions in drug administration (up to 52.9% for certain medications) without an increase in flare incidence, suggesting that tapering TNF inhibitors can be a safe and effective strategy for managing rheumatoid arthritis.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Comparing a tapering strategy to the standard dosing regimen of TNF inhibitors in rheumatoid arthritis patients with low disease activity. Plasencia, C., Wolbink, G., Krieckaert, CL., et al.[2017]

In a study involving 24 healthy subjects, low-weight training combined with blood flow restriction (BFR) resulted in significantly greater strength gains in both proximal and distal muscle groups compared to low-weight training without BFR, with increases in shoulder strength by up to 30%.

BFR training also led to significant increases in arm and forearm circumferences, indicating enhanced muscle hypertrophy, while no adverse events were reported, suggesting that this method is safe for participants.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Upper-extremity blood flow restriction: the proximal, distal, and contralateral effects-a randomized controlled trial. Bowman, EN., Elshaar, R., Milligan, H., et al.[2020]

A consensus among 15 Italian rheumatologists found that starting TNF inhibitors (TNFi) immediately in DMARDs-naïve patients with early rheumatoid arthritis (RA) does not significantly improve clinical, functional, or radiographic outcomes compared to a step-up approach within 12 weeks.

The review included 6 studies with a total of 1080 records, indicating that while TNFi can be effective, the optimal timing for its use in treatment strategies for early RA remains uncertain and requires further investigation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Immediate treatment with tumour necrosis factor inhibitors in synthetic disease-modifying anti-rheumatic drugs-naïve patients with rheumatoid arthritis: results of a modified Italian Expert Consensus. Bortoluzzi, A., Valesini, G., D'Angelo, S., et al.[2018]

In a study of 1,818 elderly patients with rheumatoid arthritis undergoing major surgeries, the timing of infliximab infusion before surgery did not affect the risk of post-operative infections or mortality.

Post-operative infection rates varied among different surgical procedures, but there was no increased risk associated with receiving infliximab closer to the time of surgery, suggesting that withholding TNF inhibitors may not be necessary.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Pre-operative withholding of infliximab and the risk of infections after major surgery in patients with rheumatoid arthritis. Ward, MM., Dasgupta, A.[2021]

Tumor necrosis factor inhibitors (TNFi) are effective biologic therapies for rheumatoid arthritis (RA) with a proven clinical efficacy, but they are associated with a range of potential adverse events, from mild to serious.

Despite the risks, the overall safety profile of TNFi is reasonable, and with proper screening and ongoing monitoring, the benefits of treatment generally outweigh the risks, especially when compared to the dangers of untreated RA.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The safety of tumor necrosis factor-alpha inhibitors in the treatment of rheumatoid arthritis. Hernández, MV., Sanmartí, R., Cañete, JD.[2017]

In a study involving 97 rheumatoid arthritis patients, tapering TNF inhibitor doses by 33% did not lead to an increase in disease flares, suggesting it is a safe option for patients in sustained remission.

However, tapering by 66% resulted in a higher risk of disease flares, indicating that while some reduction in medication may be feasible, larger reductions could compromise patient stability.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Optimizing treatment with tumour necrosis factor inhibitors in rheumatoid arthritis-a proof of principle and exploratory trial: is dose tapering practical in good responders? Ibrahim, F., Lorente-Cánovas, B., Doré, CJ., et al.[2022]

Blood flow restriction (BFR) training is considered a safe and effective method for improving musculoskeletal training outcomes, supported by 25 years of research.

There is a need for standardized, evidence-based protocols for BFR training among health professionals in South Africa to ensure its proper and safe application during rehabilitation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Blood flow restriction training in South Africa - a panel discussion. Evans, RW., Ganda, J., van Schalkwyk, L., et al.[2023]

Blood flow restriction (BFR) training, when combined with traditional resistance training, can significantly enhance strength in healthy athletes, with 78% of studies showing notable improvements compared to control groups.

BFR training also has the potential to increase muscle size and improve sport-specific performance metrics, with 50% of studies reporting muscle size gains and 75% showing enhancements in athletic performance measures.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Blood Flow Restriction Training for Athletes: A Systematic Review. Wortman, RJ., Brown, SM., Savage-Elliott, I., et al.[2021]

Tourniquets are effective in providing blood-free surgical fields in orthopaedic surgery, but they carry risks of nerve, muscle, and tissue injuries; however, advancements in tourniquet technology have reduced these risks by lowering pressure levels.

Recent evidence shows that tourniquets can also be used for blood flow restriction (BFR) therapy, which helps reduce muscle atrophy and improve strength, thus enhancing recovery outcomes when used appropriately.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Tourniquet-induced nerve compression injuries are caused by high pressure levels and gradients - a review of the evidence to guide safe surgical, pre-hospital and blood flow restriction usage. Masri, BA., Eisen, A., Duncan, CP., et al.[2020]

Citations

1. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC7727417/

A SYSTEMATIC REVIEW OF THE EFFECTS OF BLOOD ... ACL reconstruction often results in an extended period of muscle atrophy and weakness. Blood flow restriction (BFR) training is a technique that has been shown ...

2. clinicaltrials.gov clinicaltrials.gov/study/NCT04390035

BFRT in Adolescents After ACL Reconstruction This is an interventional study that will examine effects of blood flow restriction training (BFRT) in adolescents aged 12-18 after anterior cruciate ...

3. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC11092532/

Outcomes of Blood Flow Restriction Training After ACL ... In elite NCAA Division I athletes, a statistically significant delay was observed in RTS with BFRT compared with standardized physical therapy alone after ...

4. clinicaltrials.gov clinicaltrials.gov/ct2/show/NCT05754632

Study Details | NCT05754632 | The Impact of Blood Flow ... This study aims to evaluate the use of BFRT in conjunction with traditional anterior ligament reconstruction (ACLR) rehabilitation in adolescents. The purpose ...

5. delfimedical.com delfimedical.com/pts-for-bfr/

PTS for BFR System - Delfi Medical The PTS Personalized Tourniquet System for Blood Flow Restriction (BFR) has been specifically designed to safely regulate and control tourniquet pressure.

6. delfimedical.com delfimedical.com/personalized-bfr/

Personalized BFR - Delfi Medical Delfi's Personalized Tourniquet System for Blood Flow Restriction facilitates the safe use of proven BFR rehabilitation training methods.