Blood Flow Restriction to Improve Muscle Strength After ACL Injury
Condition: Anterior Cruciate Ligament Injury
MeSH terms: Wounds and Injuries; Anterior Cruciate Ligament Injuries
Study type: Interventional

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)
    

Intervention name(s): DELFI PTS Personalized Tourniquet System for Blood Flow Restriction Training; Eccentric Exercise with BLAST Leg Press System; Concentric Exercise with BLAST Leg Press System
Intervention type(s): Device; Other; Other
Intervention description(s): cuff is inflated to 80% of an individuals limb occlusion pressure; 4 sets of 10 repetitions of an eccentric leg press exercise performed at 70% of the 1 repetition maximum; 4 sets of 10 repetitions of an concentric leg press exercise performed at 70% of the 1 repetition maximum
Other intervention name(s): Kaatsu Training
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: ACL; Knee; Muscle