Blood Flow Restriction to Improve Muscle Strength After ACL Injury

Blood Flow Restriction Training to Improve Muscle Strength and Function Following Anterior Cruciate Ligament Injury

Quadriceps muscle weakness is a common consequence following anterior cruciate ligament (ACL) injury and reconstruction. Maximizing quadriceps strength following ACL injury is significant as diminished quadriceps strength has been linked to the osteoarthritis that affects over 50% of surgically reconstructed limbs. Given that knee joint health following ACL injury is predicated on restoring quadriceps strength, identifying treatment approaches capable of improving strength is paramount. Blood flow restriction training (BFRT) is a method where oxygen to the muscle is intentionally reduced during exercise/rehabilitation and may lead to more timely and substantial strength gains. In the proposed project, we will examine the efficacy of BFRT in patients who have undergone ACL reconstruction and suffer from substantial quadriceps weakness.

Study Overview

• Status: Completed
• Conditions: Anterior Cruciate Ligament Injury
• Intervention / Treatment: Device: DELFI PTS Personalized Tourniquet System for Blood Flow Restriction Training; Other: Eccentric Exercise with BLAST Leg Press System; Other: Concentric Exercise with BLAST Leg Press System

Detailed Description

Quadriceps muscle weakness is a common consequence following anterior cruciate ligament (ACL) injury and reconstruction. Maximizing quadriceps strength following ACL injury is significant as diminished quadriceps strength has been linked to the osteoarthritis that affects over 50% of surgically reconstructed limbs. Given that knee joint health following ACL injury is predicated on restoring quadriceps strength, identifying treatment approaches capable of improving strength is paramount. Blood flow restriction training (BFRT) is a method whereby oxygen to the muscle is intentionally reduced during exercise/rehabilitation and may lead to more timely and substantial strength gains. In the proposed project, we will examine the efficacy of BFRT in patients who have undergone ACL reconstruction and suffer from quadriceps weakness. This project will have a randomized clinical trial design. Sixty patients that have torn their ACL and plan to undergo surgical reconstruction will be randomized into one of four groups: 1) eccentric exercise; 2) concentric exercise; 3) eccentric exercise with blood flow restriction; or 4) concentric exercise with blood flow restriction. All patients regardless of randomization assignment will also receive standard of care ACL rehabilitation. Approximately 6 weeks after ACL reconstruction surgery, patients will begin to receive the study interventions which will last for 8 weeks. The concentric exercise will be a leg press exercise done on a conventional leg press machine, while the eccentric exercise will be a leg press exercise done on a device designed to elicit eccentric muscle contractions. Patients will train at 70% of their 1 repetition maximum and will complete 4 sets of 10 contractions at each session (2 sessions/week). For patients randomized to the BFRT groups they will complete the leg press exercise while blood flow the the quadriceps muscle is restricted with a BFRT device (Delfi Personalized Tourniquet System for Blood Flow Restriction). We will quantify our dependent variables prior to surgical reconstruction, 6 weeks post-operatively (before study intervention starts), 14 weeks post-operatively (immediately after study intervention ends), and time of physician discharge from rehabilitation (e.g. time medical clearance for return to activity). The primary outcome is isokinetic quadriceps strength. We hypothesize that patients who complete eccentric exercise along with blood flow restriction training will realize the greatest gains in muscle strength.

The DELFI PTS Personalized Tourniquet system is exempt from premarket notification and is therefore not subject to 510(k)

• Study Type: Interventional
• Enrollment (Actual): 48
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 30 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

1. suffered an acute, complete ACL rupture as confirmed by MRI
2. scheduled to undergo ACL reconstruction
3. scheduled to undergo ACL reconstruction with a surgeon affiliated with MedSport (University of Michigan Orthopaedic Clinic)
4. willing to undergo rehabilitation through MedSport (University of Michigan Orthopaedic Clinic) 5)) Willingness to participate in testing and follow-up as outlined in the protocol

6) English-speaking

Exclusion Criteria:

1. inability to provide written informed consent (or assent)
2. female subjects who are pregnant or are planning to become pregnant during the study timeframe
3. previous ACL injury
4. previous surgery to either knee
5. bony fracture accompanying ACL injury
6. chronic ACL injuries (for our study, this is defined as patient reporting to a physician greater than 2 weeks after initial injury)
7. patients who experienced a knee dislocation
8. History of blood clots
9. Previous deep vein thrombosis
10. Use of estrogen or progestin contraceptive
11. History of cerebrovascular disease
12. History of peripheral vascular disease
13. History of Sickle Cell Anemia
14. History of chronic muscular disorder (e.g. fibromyalgia)
15. History of severe hypertension

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

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Eccentric Exercise with Delfi Blood Flow Restriction Training; Patients randomized to the eccentric exercise + blood flow restriction training group will receive eccentric exercise two times per week for 8 weeks, beginning 8-12 weeks after anterior cruciate ligament reconstruction. Patients will completed the exercise with knee range of motion limited to 20-60 degrees of knee flexion and will train at an intensity equal to 70% of their eccentric 1-repetition maximum for 4 sets of 10 repetitions. During exercise, patients will have the DELFI personalized tourniquet system applied over the quadriceps to restrict blood flow. The tourniquet will be set to a limb occlusion pressure of 80%.	Device: DELFI PTS Personalized Tourniquet System for Blood Flow Restriction Training; cuff is inflated to 80% of an individuals limb occlusion pressure; Other Names: Kaatsu Training; Other: Eccentric Exercise with BLAST Leg Press System; 4 sets of 10 repetitions of an eccentric leg press exercise performed at 70% of the 1 repetition maximum
Experimental: Concentric Exercise with Delfi Blood Flow Restriction Training; Patients randomized to the concentric exercise group will receive concentric exercise two times per week for 8 weeks, beginning 8-12 weeks after anterior cruciate ligament reconstruction. Patients will completed the exercise with knee range of motion limited to 20-60 degrees of knee flexion and will train at an intensity equal to 70% of their concentric 1-repetition maximum for 4 sets of 10 repetitions.	Device: DELFI PTS Personalized Tourniquet System for Blood Flow Restriction Training; cuff is inflated to 80% of an individuals limb occlusion pressure; Other Names: Kaatsu Training; Other: Concentric Exercise with BLAST Leg Press System; 4 sets of 10 repetitions of an concentric leg press exercise performed at 70% of the 1 repetition maximum
Active Comparator: Eccentric Exercise; Patients randomized to the eccentric exercise group will receive eccentric exercise two times per week for 8 weeks, beginning 8-12 weeks after anterior cruciate ligament reconstruction. Patients will completed the exercise with knee range of motion limited to 20-60 degrees of knee flexion and will train at an intensity equal to 70% of their eccentric 1-repetition maximum for 4 sets of 10 repetitions.	Other: Eccentric Exercise with BLAST Leg Press System; 4 sets of 10 repetitions of an eccentric leg press exercise performed at 70% of the 1 repetition maximum
Active Comparator: Concentric Exercise; Patients randomized to the concentric exercise group will receive concentric exercise two times per week for 8 weeks, beginning 8-12 weeks after anterior cruciate ligament reconstruction. Patients will completed the exercise with knee range of motion limited to 20-60 degrees of knee flexion and will train at an intensity equal to 70% of their concentric 1-repetition maximum for 4 sets of 10 repetitions. During exercise, patients will have the DELFI personalized tourniquet system applied over the quadriceps to restrict blood flow. The tourniquet will be set to a limb occlusion pressure of 80%.	Other: Concentric Exercise with BLAST Leg Press System; 4 sets of 10 repetitions of an concentric leg press exercise performed at 70% of the 1 repetition maximum

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline to return to activity in quadriceps muscle strength	concentric isokinetic muscle strength at 60 degrees per second	Pre-surgery (baseline), Return to Activity (~9 months post-surgery)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Knee Flexion Angle	Peak knee flexion angle recorded during a single-legged hop (units: degrees)	Return to Activity (~9 months post-surgery)
Knee Flexion Moment	Peak knee flexion moment recorded during a single-legged hop (units: Nm/kg)	Return to Activity (~9 months post-surgery)
Change from baseline to pre-intervention in PROMIS Global Health Scale	Patient-reported outcome measured to assess health related quality of life. Physical Function Average: t score = 50±10 Min: 10 Max: 90	Pre-surgery (baseline), Pre-intervention (~10 weeks post-surgery)
Change from baseline to post-intervention in PROMIS Global Health Scale	Patient-reported outcome measured to assess health related quality of life. Physical Function Average: t score = 50±10 Min: 10 Max: 90	Pre-surgery (baseline), Post-intervention (~18 weeks post-surgery)
Change from baseline to return to activity in PROMIS Global Health Scale	Patient-reported outcome measured to assess health related quality of life. Physical Function Average: t score = 50±10 Min: 10 Max: 90	Pre-surgery (baseline),Return to Activity (~9 months post-surgery)

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline to pre-intervention in quadriceps cross-sectional area	cross-sectional area of the quadriceps muscle	Pre-surgery (baseline), Pre-intervention (~10 weeks post-surgery)
Change from baseline to post-intervention in quadriceps cross-sectional area	cross-sectional area of the quadriceps muscle	Pre-surgery (baseline), Post-intervention (~18 weeks post-surgery)
Change from baseline to return to activity in quadriceps cross-sectional area	cross-sectional area of the quadriceps muscle	Pre-surgery (baseline), Return to Activity (~9 months post-surgery)

Collaborators and Investigators

• Sponsor: University of Michigan

Publications and helpful links

General Publications

• Curran MT, Bedi A, Mendias CL, Wojtys EM, Kujawa MV, Palmieri-Smith RM. Blood Flow Restriction Training Applied With High-Intensity Exercise Does Not Improve Quadriceps Muscle Function After Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial. Am J Sports Med. 2020 Mar;48(4):825-837. doi: 10.1177/0363546520904008.

Study record dates

Study Major Dates

• Study Start (Actual): August 25, 2016
• Primary Completion (Actual): November 21, 2018
• Study Completion (Actual): November 21, 2018

Study Registration Dates

• First Submitted: April 17, 2017
• First Submitted That Met QC Criteria: May 2, 2017
• First Posted (Actual): May 5, 2017

Study Record Updates

• Last Update Posted (Actual): January 23, 2019
• Last Update Submitted That Met QC Criteria: January 19, 2019
• Last Verified: January 1, 2019

More Information

Terms related to this study

• Keywords: ACL; Knee; Muscle
• Additional Relevant MeSH Terms: Leg Injuries; Knee Injuries; Wounds and Injuries; Anterior Cruciate Ligament Injuries
• Other Study ID Numbers: HUM00110455

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: No