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

Study Overview
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Brief Summary
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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?

Detailed Description
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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.

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

Conditions
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Anterior Cruciate Ligament Injuries, Knee Injuries, Quadriceps Muscle Atrophy

Intervention / Treatment
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* Device: Blood Flow Restriction using Delfi Personalized Tourniquet System


Participation Criteria
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Eligibility Criteria
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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) 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. Exclusion Criteria: 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).

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional 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)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: BFR Intervention Group<br>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<br>* 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.<br>* Other names: FDA Establishment Registration Number 9681444. Device Listing Number E127474. Classification Number 878.5910. Product Code KCY. 510(k) Exempt. MID: XCDELMED1099VAN;|
| No Intervention: No Intervention/Control Group<br>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 | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quadriceps Hypertrophy | Thigh Circumference measured at location 10cm superior to patella and measured in cm comparing involved to uninvolved lower extremity | Change in strength at Pre-op, 8 weeks, 3months post-op, 6months, 9 months post-op | 
| 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). | 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 | 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 | 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 | Patient Reported Outcome Measure- The scores range from 0 to 100, with higher scores representing patients who are more ready to return to sport | Tracking change at Pre-op, 3months post-op, 6 months post-op, 9 months post-op. 2 years post-op | 
| Tegner Activity Scale | Tegner activity scale will measure sport level- higher level equals higher sport competitive level | changes from pre-operative, 9 months, and 2 years post-operative | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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rehabilitation, physical therapy