Early Postoperative Compex Rehab NMES Use for Total Knee Arthroplasty Patients
Condition: Knee Osteoarthritis
MeSH terms: Osteoarthritis; Osteoarthritis, Knee
Study type: Interventional

Summary: 
      This study will examine the effects, if any, of using muscle stimulation on the quadriceps
      following a total knee replacement. Secondary objectives will be to evaluate and compare pain
      levels, qualitative outcomes, and the impact of NMES on pain medication requests between
      groups. It is possible that strengthening the quadriceps muscles and improving their
      activation will reduce postoperative pain and help patients return to activities sooner than
      with standard therapy alone.
    

Detailed description: 
      Neuromuscular electrical stimulation (NMES) for muscle strengthening and training has been in
      use since the 1970s, but questions still remain regarding its effectiveness with different
      patient populations, the duration of use and specifics regarding the stimulation itself, such
      as length and type of electrical impulse. NMES works by passing electrical impulses through
      the muscles to get them to contract. These impulses mimic the body's natural neural activity
      (action potential) to cause a contraction. The goal with NMES is to strengthen the muscle
      sooner by using muscle re-education. The quadriceps is weakened and sometimes slow to respond
      after knee surgery. A weak quadriceps muscle after surgery can be a contributing factor to
      dissatisfaction with the surgical result. When the quadriceps are weak or not firing
      properly, forces are transferred to areas such as the knee joint placing an additional strain
      on the replaced joint and contributing to knee pain, swelling and inflammation. If we can get
      patients' quads firing better and sooner, we hope we would also see better short-term and
      long-term functional outcomes and more long-term satisfaction than is presently reported.
      Study Enrollment We are looking for 60 patients to participate. We are randomly assigning 30
      participants to receive the standard therapy regimen and 30 to follow the standard therapy
      regimen with the addition of using an NMES treatment twice a day, every day, for a ten-week
      period. Patients in the therapy with NMES treatment group will keep a tracking log of their
      use at home and will turn in the units at the 10-week appointment. The unit is easy to use
      and all participants are given specific instructions on its use. All participants complete
      baseline muscle testing before their surgery and then again at two-week, six-week, ten-week,
      and one-year appointments. The muscle testing consists of a battery of functional measures to
      assess the quadriceps such as the Timed Up and Go test (TUG), Six Minute Walk test (6MWT),
      Single Limb Stance (SLS) and others. All testing is conducted at Indiana Orthopaedic Hospital
      South's physical therapy department.

      When designing this study we worked closely with the department to make sure the intended
      tests were appropriate both for our study and the facility; the input from the staff was and
      continues to be integral to this study's success. It is too early to report any findings and
      we are still enrolling patients. If effective, the NMES treatment should improve quadriceps
      activation and functioning early on after surgery, which will hopefully allow the patient to
      experience less pain and have a quicker functional recovery than a patient who did not use
      the NMES. Only time will tell if this is a logical conclusion and if NMES as a standard
      postoperative therapy would be beneficial for our patients. We anxiously await the outcome of
      the study.
    

Intervention name(s): Compex Rehab
Intervention type(s): Device
Intervention description(s): Participants in this arm will use a Compex® Rehab unit for neuromuscular electrical stimulation starting with postoperative at-home day 1 and continue using the unit twice a day, every day, until a 10-week follow-up is reached. The unit produces a 380 microsecond biphasic curve and utilizes a four phase process for the treatment ("Warm-up", "Work", "Relaxation", and "Recovery") for a total treatment time of 20 minutes and 5 seconds per session. All frequencies are delivered at the maximum subjective tolerable intensity. Participants will control this intensity and be asked to select a level that is tolerable although mildly uncomfortable; they will be instructed to increase this intensity as tolerated.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Supportive Care