Combined NMES and BFR Training After TKA

Study Overview
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Brief Summary
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The purpose of this feasibility study is to determine the initial efficacy of early combined Neuromuscular Electrical Stimulation (NMES) and Blood Flow Restriction (BFR) in addition to standard rehabilitation in 15 subjects after Total Knee Arthroplasty (TKA). The second aim is to determine the feasibility and patient perceptions of combined NMES and BFR by assessing: 1) adherence, 2) satisfaction and 3) safety.

Detailed Description
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It's estimated that almost 3.5 million Total Knee Arthroplasties (TKA) will be performed annually by 2030. Despite initiating rehabilitation within 48 hours of surgery, up to a 60% strength loss is noted in the quadriceps one month after TKA. This weakness persists for years after surgery and is associated with decreased gait speed, balance, stair climbing ability and is associated with an increased risk for falls. Approximately 85% of the strength loss after TKA is explained by the combination of voluntary muscle activation deficits and muscle atrophy. Immediately postoperatively, strength loss is primarily due to activation deficits, and as time progresses, muscle atrophy becomes the major contributing factor. Early in the postoperative period, Neuromuscular Electrical Stimulation (NMES) has been shown to diminish activation deficits and improve function after TKA. Blood Flow Restriction (BFR) is a proposed strength training alternative for people who are unable to tolerate traditional strength training at 70-80% of their 1 repetition maximum (1RM), such as those who have just had surgery. Performing low intensity exercise (20-30% of 1RM) with BFR has been shown to achieve similar muscle mass and strength gains when compared to high intensity resistance training. BFR has been studied in people with TKA, but it has been used later in the recovery period (>6 weeks postoperative) when the greatest strength losses have already occurred. The goal of this study is to address both factors of postoperative quadriceps weakness, activation deficit and atrophy, through the use of early NMES and BFR in addition to standard postoperative rehabilitation in an attempt to minimize strength loss and improve functional outcomes. AIM 1: To determine the initial efficacy of combined neuromuscular electrical stimulation and blood flow restriction training (COMBO) on strength (primary outcome), activation, pain, range of motion, and function compared to historical controls. Hypothesis 1.1: The COMBO group will have greater attenuation of early postoperative strength losses and improved pain, ROM, and function compared to historical controls. AIM 2: To determine the feasibility of COMBO by assessing 1) adherence, 2) satisfaction, and 3) safety Hypothesis 2.1: An 80% adherence rate to the intervention will be observed. Hypothesis 2.2: Study participants will indicate acceptability of COMBO with a satisfaction survey median score of at least 4/5 (somewhat satisfied). Hypothesis 2.3: There will be no intervention-related Adverse Events or Serious Adverse Events during the 8-week protocol.

Official Title
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Combined Neuromuscular Electrical Stimulation and Blood Flow Restriction Training After Total Knee Arthroplasty

Conditions
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Total Knee Arthroplasty

Intervention / Treatment
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* Procedure: Standard Rehabilitation + Neuromuscular Electrical Stimulation and Blood Flow Restriction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Scheduled to undergo primary unilateral total knee arthroplasty secondary to end-stage osteoarthritis Exclusion Criteria: BMI > 40 kgm2 Current smoker or history of drug abuse Comorbid conditions that substantially limit physical function or would interfere with the participant's ability to successfully complete rehabilitation (e.g. neurologic, vascular, cardiac problems, or ongoing medical treatments) Unstable orthopedic conditions that limit function Uncontrolled diabetes (hemoglobin A1c level > 8.0) Pregnancy Preoperative ROM less than 10-120 degrees Demand cardiac pacemaker or unstable arrhythmia Prior history of DVT/PE Thrombophilia or other clotting disorders Sickle cell trait/anemia History of peripheral vascular disease Patient report of easy bruising

Ages Eligible for Study
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Minimum Age: 50 Years
Maximum Age: 85 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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: COMBO<br>Neuromuscular Electrical Stimulation and Blood Flow Restriction (COMBO) in addition to standard postoperative rehabilitation. | Procedure: Standard Rehabilitation + Neuromuscular Electrical Stimulation and Blood Flow Restriction<br>* Subjects will begin a standardized protocol on post-op day 2. Outpatient visits will be 2x/wk for weeks 0-4 and then 1x/wk for weeks 5-8. Subjects will utilize NMES on the quadriceps in the home setting 2x/day for the first 3-4 weeks during isometric contractions at their highest tolerated intensity. Total treatment will begin at 10 minutes. At the end of post-op week 2, subjects will be exposed in clinic to BFR on the surgical limb increasing to 80% limb occlusion pressure over weeks 3-4 as tolerated. Initially, BFR and NMES will be performed simultaneously. BFR will then be progressed using active exercises. After completing a safety checklist, subjects will be issued a home BFR unit for use 2x/week (3x total including clinic visit) at which time NMES will be discontinued. BFR exercise intensity will be progressed as tolerated to maintain 20-30% of 1RM.<br>* Other names: NMES;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Quadriceps Strength From Baseline to 8 Weeks | Assesses the maximal voluntary isometric contraction strength of the quadriceps muscle using an electromechanical dynamometer. | Baseline, 4 weeks and 8 weeks after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Quadriceps Activation From Baseline to 8 Weeks | Assesses voluntary activation of the quadriceps using the doublet interpolation technique, where a supramaximal stimulus is applied during a maximal voluntary isometric contraction and again immediately afterward, while the quadriceps muscle is at rest. | Baseline, 4 weeks and 8 weeks after surgery | 
| Change in Knee Range of Motion (ROM) From Baseline to 8 Weeks | Assesses the mobility of the knee joint. Knee ROM will be measured in the supine position both actively and passively using a long-arm goniometer. | Baseline, 4 weeks and 8 weeks after surgery | 
| Change in Timed Up and Go (TUG) From Baseline to 8 Weeks | Evaluates mobility through the time required to rise from an arm chair, walk 3 meters, turn and walk back to the arm chair, and return to a seated position. | Baseline, 4 weeks and 8 weeks after surgery | 
| Change in 30-Second Sit-to-Stand Test (30-STS) From Baseline to 8 Weeks | Assesses lower body strength and the fatigue effect caused by the number of sit-to-stand repetitions that can performed in 30 seconds. | Baseline, 4 weeks and 8 weeks after surgery | 
| Change in Stair Climbing Test From Baseline to 8 Weeks | Assesses lower body strength, power and balance as measured through the time required to ascend and descend a flight of stairs. Measures a higher level of function that minimizes the possibility of a ceiling effect. | Baseline, 4 weeks and 8 weeks after surgery | 
| Change in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) From Baseline to 8 Weeks | Assesses self-reported physical function. Scales assess pain, stiffness, and physical function in patients with hip and / or knee osteoarthritis. Total score range is 0-96. Total score is computed by summing three subscales: pain (range 0-20), stiffness (range 0-8), and functional limitations (range 0-68), then dividing by total points possible. Higher scores indicate worse pain, stiffness, and functional limitations. | Baseline, 4 weeks and 8 weeks after surgery | 
| Adherence to the Intervention as measured by home exercise program logs | Assesses the adherence of subjects and informs feasibility of intervention. Measured by home exercise program logs. | 4 weeks and 8 weeks after surgery | 
| Satisfaction with Rehabilitation Program as measured by a 5-point Likert scale ranging from very unsatisfied to very satisfied. | Assesses the satisfaction of subjects using a 5-point Likert scale ranging from very unsatisfied to very satisfied in each of the following rehabilitation program components: overall rehabilitation program, BFR, NMES, and home exercise program. Informs feasibility of intervention. | 8 weeks after surgery | 
| Safety of COMBO program as measured by adverse events reported per IRB procedures. | Assess safety of intervention as measured by adverse events related to the COMBO program reported per IRB procedures. Adverse events will be documented at all clinic and testing sessions. | 4 weeks and 8 weeks after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Blood Flow Restriction, Neuromuscular Electrical Stimulation, BFR, NMES, Rehabilitation