Anterior Cruciate Ligament Injury
Conditions
Keywords
ACL, Knee, Muscle
Brief 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.
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)
Interventions
DEVICEDELFI PTS Personalized Tourniquet System for Blood Flow Restriction Training
cuff is inflated to 80% of an individuals limb occlusion pressure
OTHEREccentric 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
OTHERConcentric 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
Sponsors
University of Michigan
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
14 Years to 30 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline to return to activity in quadriceps muscle strength | Pre-surgery (baseline), Return to Activity (~9 months post-surgery) | concentric isokinetic muscle strength at 60 degrees per second |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Knee Flexion Moment | Return to Activity (~9 months post-surgery) | Peak knee flexion moment recorded during a single-legged hop (units: Nm/kg) |
| Change from baseline to pre-intervention in PROMIS Global Health Scale | Pre-surgery (baseline), Pre-intervention (~10 weeks post-surgery) | Patient-reported outcome measured to assess health related quality of life. Physical Function Average: t score = 50±10 Min: 10 Max: 90 |
| Change from baseline to post-intervention in PROMIS Global Health Scale | Pre-surgery (baseline), Post-intervention (~18 weeks post-surgery) | Patient-reported outcome measured to assess health related quality of life. Physical Function Average: t score = 50±10 Min: 10 Max: 90 |
| Change from baseline to return to activity in PROMIS Global Health Scale | Pre-surgery (baseline),Return to Activity (~9 months post-surgery) | Patient-reported outcome measured to assess health related quality of life. Physical Function Average: t score = 50±10 Min: 10 Max: 90 |
| Knee Flexion Angle | Return to Activity (~9 months post-surgery) | Peak knee flexion angle recorded during a single-legged hop (units: degrees) |
Other
| Measure | Time frame | Description |
|---|---|---|
| Change from baseline to return to activity in quadriceps cross-sectional area | Pre-surgery (baseline), Return to Activity (~9 months post-surgery) | cross-sectional area of the quadriceps muscle |
| Change from baseline to post-intervention in quadriceps cross-sectional area | Pre-surgery (baseline), Post-intervention (~18 weeks post-surgery) | cross-sectional area of the quadriceps muscle |
| Change from baseline to pre-intervention in quadriceps cross-sectional area | Pre-surgery (baseline), Pre-intervention (~10 weeks post-surgery) | cross-sectional area of the quadriceps muscle |
Countries
United States
Outcome results
None listed