Optimizing Movement After ACL Injury

Study Overview
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Brief Summary
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This study will evaluate if a visual biofeedback program leads to improved knee outcomes after anterior cruciate ligament reconstruction. Outcome measures will include biomechanical movement patterns and markers of knee osteoarthritis on magnetic resonance imaging.

Detailed Description
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Fifty percent of teenagers and young adults who suffer an anterior cruciate ligament (ACL) injury develop radiographic knee osteoarthritis (OA) within 15 years. The resulting pain, reduced quality-of-life, and increased risk for co-morbidity lead to substantial healthcare costs, inability to fulfill work and personal responsibilities, and reduced long-term health. Articular cartilage degeneration is the hallmark sign of early OA development after knee injury. This deterioration can be measured by increased T2 and T1rho relaxation time on quantitative magnetic resonance imaging (MRI), an imaging biomarker for OA development. Harmful increases in MRI markers of the knee's articular cartilage occur within months of ACL injury and indicate preventative interventions should begin soon after injury. However, evidence-based interventions to prevent OA do not exist. The investigators have shown that after ACL reconstruction (ACLR), patients exhibit asymmetric movement patterns characterized by up to 62% lower knee joint loading during walking and squatting in the injured limb at two months after ACLR. These knee joint loading patterns remain 40% lower at six months. Emerging evidence suggests knee joint unloading patterns after ACL injury may increase the risk for OA development. Currently, no studies have examined the efficacy of movement-focused interventions during the first months after ACLR, which explains the lack of evidence-based interventions that successfully increase knee loading early after ACLR. This gap presents a barrier to the research team's long-term goal of preventing OA in young, active individuals before irreversible knee degeneration occurs. This project will challenge the traditional OA paradigm that too much joint loading (e.g. wear and tear) causes cartilage breakdown. The multi-disciplinary team spanning rehabilitation, orthopaedics, radiology and biomechanics has developed a novel visual biofeedback paradigm using portable force plates that can increase knee loading during squats within a single session after ACLR. This data suggest movement is modifiable using visual feedback, but its efficacy beyond a single training session is unknown. This study will determine the efficacy of the visual biofeedback program initiated two weeks after ACLR by assessing movement biomechanics and MRI changes in cartilage microstructure six months later. Successful completion of this project will establish the first rehabilitation intervention to effectively and optimally load the knee joint early after ACLR, providing the initial steps in the team's work to prevent OA after ACL injury.

Official Title
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Optimizing Movement After Anterior Cruciate Ligament Injury

Conditions
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Knee Osteoarthritis, Anterior Cruciate Ligament Injuries

Intervention / Treatment
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* Procedure: Squat Biofeedback
* Procedure: Standard Care


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: acute ACL injury in the past 6 months have had ACL reconstruction in the past month or have a planned ACL reconstruction Exclusion Criteria: previous knee injury or surgery (contralateral knee) body mass index over 35 kg/m2 concomitant posterior cruciate ligament reconstruction or cartilage procedure that include extended weightbearing restrictions and/or changes to cartilage structure current pregnancy planned pregnancy during study duration

Ages Eligible for Study
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Minimum Age: 13 Years
Maximum Age: 35 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: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Control<br>Standard care. | Procedure: Standard Care<br>* Standard care post-operative physical therapy<br>|
| Experimental: Experimental<br>Squat biofeedback intervention. | Procedure: Squat Biofeedback<br>* The intervention group will complete bilateral squats with each limb on a separate portable force plate. They will receive real-time visual feedback on a 32-inch screen during all squats. Biofeedback conditions will be progressed from simplest (ground reaction force only) to most complex (ground reaction force plus center of pressure). This intervention will be included in additional to standard care post-operative physical therapy.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Knee flexion moment impulse | Between-limb ratio of knee flexion moment impulse during descent and ascent phase of bilateral squat | Immediately after the intervention | 
| Cartilage T2 relaxation time | Percent change in cartilage T2 relaxation time from 2 weeks to 6 months after ACL reconstruction | 6 months after ACL reconstruction | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Knee flexion moment impulse | Between-limb ratio of knee flexion moment impulse during descent and ascent phase of bilateral squat | 6 months after ACL reconstruction | 
| Peak knee flexion moment | Between-limb ratio of peak flexion moment during gait | Immediately after the intervention | 
| Peak knee flexion moment | Between-limb ratio of peak flexion moment during gait | 6 months after ACL reconstruction | 
| Quadriceps strength | Between-limb ratio of isometric and isokinetic quadriceps strength | Immediately after the intervention | 
| Quadriceps strength | Between-limb ratio of isometric and isokinetic quadriceps strength | 6 months after ACL reconstruction |