BFR Therapy for Post-Op Rehab of ACL Reconstruction With Quadriceps Tendon Autograft

Study Overview
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Brief Summary
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The overall objective of the proposed research is to conduct a prospective, randomized controlled trial to investigate whether the addition of BFR therapy to standard post-operative rehabilitation regimen significantly improves clinical outcomes following anterior cruciate ligament reconstruction (ACLR) standardized with respect to both surgical technique and graft selection. Patients indicated for ACLR will be screened and offered enrollment into this prospective, randomized controlled trial. MRI of bilateral thighs will be performed within 7 days of ACLR. Patients will be randomized to either REHAB or REHAB + BFR (study intervention) using a block randomization scheme. Patients will undergo repeat MRI of bilateral thighs pre-surgery, at 12 weeks, and at 52 weeks post-operatively (primary outcome measure.) Patient reported outcome (PRO) instruments will be administered pre-operatively to establish pre-operative debility related to ACL injury and subsequently after ACLR at 24 weeks, 36 weeks, and 52 weeks post-operative (secondary outcome measures).

Detailed Description
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The overall objective of the proposed research is to conduct a prospective, randomized controlled trial to investigate whether the addition of BFR therapy to standard post-operative rehabilitation regimen significantly improves clinical outcomes following ACLR standardized with respect to both surgical technique and graft selection. The investigator's central hypothesis is that the addition of BFR therapy has the potential to accelerate surgical recovery, expedite return-to-duty, and maximize medical readiness following ACLR. In the proposed trial validated patient reported outcome measures will be used to assess for functional clinical improvement, while quadriceps musculature cross sectional area (CSA) as measured on MRI will be used to quantify the effect of therapy on quadriceps strength. The rationale for using this modality is based upon the fact that the measurement of quadriceps CSA and muscle volume as surrogates for overall quadriceps function is well described, and a number of studies have convincingly demonstrated positive correlations between these parameters and quadriceps strength4, 17. However, in spite of these reports, the acceptance acknowledging MRI as a surrogate for quadriceps strength remains limited. Therefore, isokinetic and isometric quadriceps strength of both the operative and non-operative knee extensors (quadriceps) will be measured pre-operatively within 7-10 days approximately prior to ACLR and post-operatively at approximately 12 weeks, 24 weeks, 36 weeks, and 52 weeks. MRI of bilateral thighs will be performed immediately prior to ACLR to establish a baseline CSA in the operative and non-operative lower extremity. Then a repeat MRI will be performed following the conclusion of a standardized 12-week (approximately) post-operative rehabilitation regimen among patients randomized to either a standard rehabilitation regimen (REHAB) or a rehabilitation regimen with BFR (REHAB + BFR.) Finally, MRI will be repeated at 52 weeks post-operative to examine for latent changes in CSA once patients have been returned to unrestricted physical activities. AIM 1: To determine if the addition of BFR therapy to a standard post-operative rehabilitation protocol increases quadriceps muscle cross sectional area and volume after ACLR as measured with magnetic resonance imaging (MRI). Hypothesis: The addition of BFR therapy to a standard post-operative rehabilitation regimen following ACLR will increase quadriceps muscle CSA and volume when compared to a standard post-operative rehabilitation regimen measured at approximately 12-weeks post-operative. AIM 2: To determine if any observed increases in quadriceps muscle CSA and volume are sustained beyond the cessation of BFR therapy at approximately 12-weeks post-operative by performing repeat MRI at 52 weeks post-operative. Hypothesis: Observed increases in quadriceps muscle CSA and volume will be sustained beyond the cessation of BFR therapy at 52 weeks post-operative. AIM 3: To determine if CSA measurements obtained by MRI reliably predict knee extensor strength. Hypothesis: CSA measurements obtained by MRI reliably predict knee extensor strength as measured by isokinetic and isometric testing. AIM 4: To determine if the addition of BFR therapy to a standard post-operative rehabilitation regimen following ACLR results in significantly improved functional outcomes when compared to a standard post-operative rehabilitation regimen at 24, 36, and 52 weeks post-operative using patient reported outcomes (PRO). Hypothesis: The addition of BFR therapy to a standard post-operative rehabilitation regimen following ACLR will result in significantly improved PRO when compared to a standard post-operative rehabilitation regimen at 24, 36, and 52-weeks post-operative.

Official Title
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Blood Flow Restriction Therapy for the Post-Operative Rehabilitation of Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Autograft: A Randomized, Controlled Trial

Conditions
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ACL Injury

Intervention / Treatment
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* Other: Blood Flow Restriction (BFR) therapy
* Other: Standard REHAB


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Active duty member or Department of Defense Military Health System beneficiary 15 to 45 years of age Indicated for ACL reconstruction with quadriceps tendon autograft with evidence of skeletal maturity; no open physes/growth plates Exclusion Criteria: Patients undergoing a concomitant surgical procedure that would otherwise require a period of immobilization and/or restricted weight bearing (i.e. meniscal repair, meniscal allograft transplantation, osteochondral allograft transplantation, high tibial osteotomy) will be excluded. Undergoing combined multiligamentous knee injury reconstruction Unable to consistently participate in the prescribed post-operative rehabilitation regimen No patients with a history of recent lower extremity deep vein thrombosis, within the 12 months or on active treatment with anticoagulants, a history of ipsilateral lower extremity lymph node dissection or a history of endothelial dysfunction. Patients that are unable to obtain MRI secondary to either intolerance and/or implanted medical devices that preclude the safe completion of the MRI.

Ages Eligible for Study
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Minimum Age: 15 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: Patients will be randomized to either REHAB or REHAB + BFR (study intervention) using a block randomization scheme.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: REHAB<br>Standard post-operative rehabilitation regimen (REHAB) (Control) | Other: Standard REHAB<br>* Standard post-operative rehabilitation regimen (REHAB) beginning after first MD follow up appointment ACL reconstruction with quadriceps tendon autograft and the following functional criteria have been met: 1.) incisions healing or healed without signs of infection or dehiscence. 2.) ROM to at least 90 degree flexion. 3.) Able to perform unilateral weight bearing for 5 seconds. 4.) Pain under control and minimal knee effusion<br>|
| Experimental: REHAB + BFR<br>Standard rehabilitation regimen with BFR therapy (REHAB + BFR) (Experimental) | Other: Blood Flow Restriction (BFR) therapy<br>* BFR therapy beginning after first MD follow up appointment after ACL reconstruction with quadriceps tendon autograft and the following functional criteria have been met: 1.) incisions healing or healed without signs of infection or dehiscence. 2.) ROM to at least 90 degree flexion. 3.) Able to perform unilateral weight bearing for 5 seconds. 4.) Pain under control and minimal knee effusion.<br>Other: Standard REHAB<br>* Standard post-operative rehabilitation regimen (REHAB) beginning after first MD follow up appointment ACL reconstruction with quadriceps tendon autograft and the following functional criteria have been met: 1.) incisions healing or healed without signs of infection or dehiscence. 2.) ROM to at least 90 degree flexion. 3.) Able to perform unilateral weight bearing for 5 seconds. 4.) Pain under control and minimal knee effusion<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quadriceps CSA MRI | Quadriceps CSA as measured on MRI | [Timeframe: within 7-10 days of ACLR] [Time Frame: approximately 12-14 weeks post operative] [Time Frame: approximately 52-54 weeks post-operative] | 
| Knee extensor strength | Knee extensor isokinetic and isometric strength measurements | [Time Frame: approximately withing 7-10 days of ACLR] [Time Frame: 12 weeks post operatively] [Time Frame: 24 weeks post-operatively] [Time Frame: 36 weeks post-operatively] [Time Frame: 52 weeks post-operatively] | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Patient Reported Outcome - Pain on 10 cm Visual Analog Scale (VAS) | The VAS is a unidimensional measure of pain intensity that has been frequently reported among adults. The simplest VAS is represented as a horizontal 10 cm line. The ends are defined as the extreme limits of parameter being measured (e.g. pain) oriented from the left (worst) to the right (best.) Patients are asked mark their perceived level of pain on the horizontal line. The VAS score is determined by measuring in mm from the left hand end of the horizontal line to where the patient marks. A higher score represents greater pain intensity. | [Time Frame: pre-operatively] [Time Frame: 6 months post-operatively] [Time Frame: 9 months post-operatively] [Time Frame: 12 months post-operatively] | 
| Patient Reported Outcome - Lyscholms Score | Comprised of 8 items (limp, support, locking, instability, pain, swelling, stair climbing, squatting), which patients are asked a series of questions to characterize their experiences with respect to each of these 8 items. Patients' responses are summed, with a score of 100 denoting no symptoms or debility. | [Time Frame: pre-operatively] [Time Frame: 6 months post-operatively] [Time Frame: 9 months post-operatively] [Time Frame: 12 months post-operatively] | 
| Patient Reported Outcome - International Knee Documentation Committee Form (IKDC) | This questionnaire is broken down into three categories: symptoms, sports activity, and knee function. The symptoms subscale focuses on an assessment of pain, stiffness, swelling, and the sensation of giving-way of the knee. The sports activity subscale focuses on completion of tasks such as going up and down stairs, rising from a seated position, squatting, and jumping. The knee function subscale asks the respondent to characterize their knee at present versus prior to injury. The IKDC is scored out of 100 points, with a score of 100 representing optimal knee function. | [Time Frame: pre-operatively] [Time Frame: 6 months post-operatively] [Time Frame: 9 months post-operatively] [Time Frame: 12 months post-operatively] | 
| Patient Reported Outcome - Knee Osteoarthritis Outcome Score (KOOS) | The KOOS is a comprehensive scoring system that evaluates both short and long-term consequence of knee injury. It is comprised of 42 items, which are scored separately in 5 subscales (pain (9 items), other symptoms (7 items), function in daily living (17 items), function in sport and recreation (5 items), and knee-related quality of life (5 items).) Among the strengths of the KOOS as a PRO is its inclusion of two different subscales for physical function relating to daily life, sport, and recreation. A score of 100 represents no knee symptoms, which is then converted to a percentage score to characterize a patient's overall satisfaction with their knee function. | [Time Frame: pre-operatively] [Time Frame: 6 months post-operatively] [Time Frame: 9 months post-operatively] [Time Frame: 12 months post-operatively] | 
| Connor-Davidson Resilience Scale (CD-RISC) | The CD- RISC 2, 10, or 25 item validated instrument that is self-rated assessment of psychological resiliency. This instrument has shown reliability in measuring the ability to adapt to change, the ability to deal with what comes along, the ability to cope with stress, the ability to stay focused and think clearly, the ability to not get discouraged in the face of failure, the ability to handle unpleasant feelings such as anger, pain or sadness. | [Time Frame: pre-operatively] [Time Frame: 6 months post-operatively] [Time Frame: 9 months post-operatively] [Time Frame: 12 months post-operatively] | 
| Anterior Cruciate Ligament Return to Sport after Injury (ACL-RSI) (Short version 6Q) | ACL-RSI instrument measure one's emotion, confidence, and risk appraisal when returning to sports after an ACL injury and/or reconstructive surgery. The survey consists of 12 items that are graded on a visual analogue scale from 0 points (extremely negative psychological responses) to 100 points (no negative psychological responses). The results of the survey have been found to be strongly and significantly associated with return to sport. | [Time Frame: pre-operatively] [Time Frame: 6 months post-operatively] [Time Frame: 9 months post-operatively] [Time Frame: 12 months post-operatively] | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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BFR, ACLR, Quadriceps Tendon