Blood Flow Restriction to Improve Muscle Strength After ACL Injury

Anterior Cruciate Ligament Injury Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03141801
• Other study ID #: HUM00110455
• Status: Completed
• Phase: N/A
• Start date: August 25, 2016
• Est. completion date: November 21, 2018

Study information

• Verified date: January 2019
• Source: University of Michigan
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

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)

Recruitment information / eligibility

• Status: Completed
• Enrollment: 48
• Est. completion date: November 21, 2018
• Est. primary completion date: November 21, 2018
• Accepts healthy volunteers: No
• Gender: All
• Age group: 14 Years to 30 Years

Eligibility

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

Related Conditions & MeSH terms

• Anterior Cruciate Ligament Injuries
• Anterior Cruciate Ligament Injury
• Wounds and Injuries

Intervention

Device:
• DELFI PTS Personalized Tourniquet System for Blood Flow Restriction Training
cuff is inflated to 80% of an individuals limb occlusion pressure

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
• 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

Locations

Country	Name	City	State
United States	University of Michigan	Ann Arbor	Michigan

Sponsors (1)

Lead Sponsor	Collaborator
University of Michigan

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	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)
Other	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)
Other	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)
Primary	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	Knee Flexion Angle	Peak knee flexion angle recorded during a single-legged hop (units: degrees)	Return to Activity (~9 months post-surgery)
Secondary	Knee Flexion Moment	Peak knee flexion moment recorded during a single-legged hop (units: Nm/kg)	Return to Activity (~9 months post-surgery)
Secondary	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)
Secondary	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)
Secondary	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)