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

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?

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.

Eligibility Criteria:
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).