Blood Flow Restriction Following ACL Reconstruction (BFR)

The Effect of Blood Flow Restriction Therapy Following Anterior Cruciate Ligament Reconstruction

The main objective is to determine the impact of Blood Flow Restriction (BFR) therapy, in comparison to a standard rehabilitation protocol, on preventing atrophy, improving quadriceps strength and improving functional outcomes of patients recovering from ACL reconstruction. The investigators hypothesize that patients undergoing BFR therapy after ACL reconstruction surgery will have better functional outcomes than those undergoing normal rehabilitation without BFR therapy.

Study Overview

• Status: Completed
• Conditions: Anterior Cruciate Ligament Rupture
• Intervention / Treatment: Device: Blood Flow Restriction Therapy; Other: ACL Reconstruction rehabilitation

Detailed Description

Recovery from anterior cruciate ligament (ACL) reconstruction involves early physical therapy to promote muscular development. Traditional training regimens are based on the concept that muscle growth is induced with high resistance exercises of at least 65-70% of 1-repetition maximum. Achieving a high resistance level can be challenging in the early post-surgical patient who may be limited by pain, muscle atrophy, diminished proprioception, and psychological factors. Increasing evidence has suggested that Blood Flow Restriction (BFR) in resistance training, while transmitting a decreased load (25-50% of 1-repetition maximum) across the surgical site, may provide an additional benefit of inducing muscular development similar to that of high intensity exercises .

Augmenting exercises with BFR involves an external pressure cuff applied to the proximal portion of the extremity, which is inflated to a pressure that restricts venous outflow while allowing arterial inflow to continue. This creates a physiologic environment for the patient to gain the hypertrophic effect of high resistance training, though at a lower and safer intensity. Studies suggest that BFR stimulates muscular development through an increase in metabolic stress, muscle fiber recruitment, cell swelling, and protein synthesis.

• Study Type: Interventional
• Enrollment (Actual): 49
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Virginia
    • Fairfax, Virginia, United States, 22031
      • Inova Health System

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 11 years to 48 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. Age 13-35 years at the time of surgery
2. Anterior Cruciate Ligament (ACL) reconstruction
3. Using a physical therapy center with Blood Flow Restriction capabilities.

Exclusion Criteria:

1. Concomitant ligament reconstruction
2. Concurrent procedures that require delayed weight bearing (ie: High Tibial Osteotomy (HTO), multi-ligament reconstruction, microfracture, etc)
3. History of Deep Vein Thrombosis (DVT)/Pulmonary Embolism (PE)
4. Immunocompromising conditions (ie: Rheumatoid arthritis, chronic steroid use, etc.)
5. History of coagulation disorders or current use of anticoagulants
6. Completion of physical therapy at a location not affiliated with the study
7. Pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: BFR Therapy; This group will undergo physical therapy exercises per the standard of care, with the addition of Blood Flow Restriction (BFR) utilizing a wide pressure cuff. BFR exercises will be initiated two weeks post-op, and continued for 16 weeks.	Device: Blood Flow Restriction Therapy; A wide pressure cuff will be applied to the upper thigh prior to starting strengthening exercises. The cuff is inflated to 80% of resting systolic blood pressure. The cuff remains inflated for the entirety of the exercise (4 sets of a specific movement). Once the exercises are completed, it is deflated for a minimum of one minute before the next type of exercises are started.; Other: ACL Reconstruction rehabilitation; post-operative rehabilitation according to current standards of care
Active Comparator: No BFR; This group of patients will undergo physical therapy exercises per the current standard of care after their ACL reconstruction without BFR	Other: ACL Reconstruction rehabilitation; post-operative rehabilitation according to current standards of care

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
International Knee Documentation Committee (IKDC) Questionnaire Score	The International Knee Documentation Committee (IKDC Questionnaire) is a knee-specific patient-reported outcome measure. The IKDC Questionnaire is a subjective scale that provides patients with an overall function score. The questionnaire looks at 3 categories: symptoms, sports activity, and knee function. Scores are obtained by summing the individual items, then transforming the crude total to a scaled number that ranges from 0 to 100. This final number is interpreted as a measure of function with higher scores representing higher levels of function.	Measured preoperatively and at 12 weeks post-op.
Visual Analog Score	The visual analog scale (VAS) is a validated, subjective measure for acute and chronic pain. Scores are recorded by making a handwritten mark on a 10-cm line that represents a continuum between "no pain" and "worst pain," with "no pain" corresponding to a VAS score of 0 and "worst pain" corresponding to a VAS score of 10.	Measured preoperatively, at 2-weeks post-op, 6 weeks post-op, and 12 weeks post-op
Quadriceps Tendon Strength	We will measure quadriceps tendon strength (closed chain) strength using a hand-held dynamometer placed just distal to the knee joint on the posterior calf with the patient in the supine position. The outcome will be reported biweekly as a percentage of the strength of the contralateral side, and then finally reported as a change in strength from the first measurement to the final measurement. The results reported in this data table refer to the percent strength of the operated leg when compared to the contralateral side. The change in strength results can be found in the statistical analysis section.	Tracked from initiation of therapy 2 weeks post-op through 12 weeks post-op.
Thigh Circumference	A tape measure will be used to measure the thigh circumference 15 cm proximal to the superior pole of the patella. The outcome will be reported biweekly as a percentage of the contralateral side, and then finally reported as a change in circumference from the first measurement to the final measurement. The results reported in this data table refer to the percent circumference of the operated leg when compared to the contralateral side. The change in circumference results can be found in the statistical analysis section.	Tracked in the perioperative week and then from initiation of therapy 2 weeks post-op through 12 weeks post-op.
Degrees of Knee Flexion	Degrees of knee flexion will be measured on the operative side by a licensed physical therapist. The outcome will be reported biweekly and then finally reported as a change in degrees from the first measurement to the final measurement. The results reported in this data table refer to the degrees of knee flexion at each reported time point. The change in knee flexion results can be found in the statistical analysis section.	Tracked in the perioperative week and then from initiation of therapy 2 weeks post-op through 12 weeks post-op.
Degrees of Knee Extension	Degrees of knee extension will be measured on the operative side by a licensed physical therapist, with zero degrees indicating the knee completely at extension and negative degrees indicating degrees of hyperextension. The outcome will be reported biweekly and then finally reported as a change in degrees from the first measurement to the final measurement. The results reported in this data table refer to the degrees of knee extension at each reported time point. The change in knee extension results can be found in the statistical analysis section.	Tracked in the perioperative week and then from initiation of therapy 2 weeks post-op through 12 weeks post-op.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adverse Effects	Observation of any adverse events associated with BFR therapy, such as numbness, cuff-site pain, and bruising.	Tracked from initiation of therapy 2 weeks post-op through 12 weeks post-op

Collaborators and Investigators

• Sponsor: Inova Health Care Services
• Investigators: Principal Investigator: Edward Chang, MD, Orthopedic Surgeon

Publications and helpful links

General Publications

• Takarada Y, Takazawa H, Sato Y, Takebayashi S, Tanaka Y, Ishii N. Effects of resistance exercise combined with moderate vascular occlusion on muscular function in humans. J Appl Physiol (1985). 2000 Jun;88(6):2097-106. doi: 10.1152/jappl.2000.88.6.2097.
• Ohta H, Kurosawa H, Ikeda H, Iwase Y, Satou N, Nakamura S. Low-load resistance muscular training with moderate restriction of blood flow after anterior cruciate ligament reconstruction. Acta Orthop Scand. 2003 Feb;74(1):62-8. doi: 10.1080/00016470310013680.
• Hughes L, Paton B, Rosenblatt B, Gissane C, Patterson SD. Blood flow restriction training in clinical musculoskeletal rehabilitation: a systematic review and meta-analysis. Br J Sports Med. 2017 Jul;51(13):1003-1011. doi: 10.1136/bjsports-2016-097071. Epub 2017 Mar 4.
• Iversen E, Rostad V, Larmo A. Intermittent blood flow restriction does not reduce atrophy following anterior cruciate ligament reconstruction. J Sport Health Sci. 2016 Mar;5(1):115-118. doi: 10.1016/j.jshs.2014.12.005. Epub 2015 Apr 18.
• Yasuda T, Brechue WF, Fujita T, Shirakawa J, Sato Y, Abe T. Muscle activation during low-intensity muscle contractions with restricted blood flow. J Sports Sci. 2009 Mar;27(5):479-89. doi: 10.1080/02640410802626567.
• Scott BR, Loenneke JP, Slattery KM, Dascombe BJ. Blood flow restricted exercise for athletes: A review of available evidence. J Sci Med Sport. 2016 May;19(5):360-7. doi: 10.1016/j.jsams.2015.04.014. Epub 2015 May 9.
• Suga T, Okita K, Takada S, Omokawa M, Kadoguchi T, Yokota T, Hirabayashi K, Takahashi M, Morita N, Horiuchi M, Kinugawa S, Tsutsui H. Effect of multiple set on intramuscular metabolic stress during low-intensity resistance exercise with blood flow restriction. Eur J Appl Physiol. 2012 Nov;112(11):3915-20. doi: 10.1007/s00421-012-2377-x. Epub 2012 Mar 14.
• Takada S, Okita K, Suga T, Omokawa M, Morita N, Horiuchi M, Kadoguchi T, Takahashi M, Hirabayashi K, Yokota T, Kinugawa S, Tsutsui H. Blood flow restriction exercise in sprinters and endurance runners. Med Sci Sports Exerc. 2012 Mar;44(3):413-9. doi: 10.1249/MSS.0b013e31822f39b3.

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2018
• Primary Completion (Actual): November 1, 2021
• Study Completion (Actual): October 26, 2022

Study Registration Dates

• First Submitted: November 14, 2018
• First Submitted That Met QC Criteria: November 28, 2018
• First Posted (Actual): November 29, 2018

Study Record Updates

• Last Update Posted (Estimate): December 22, 2022
• Last Update Submitted That Met QC Criteria: November 30, 2022
• Last Verified: November 1, 2022

More Information

Terms related to this study

• Keywords: ACL; rehabilitation; BFR
• Additional Relevant MeSH Terms: Wounds and Injuries; Rupture
• Other Study ID Numbers: 18-3150

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: Yes