Compare the Effects of a Standard Therapy Protocol With a 12-week Peri-Operative Program of Kneehab XP Neuromuscular Electrical Stimulation Compared to a Control Treatment in Patients Undergoing Total Knee Replacement

• Positive PASS [ Time Frame: measured at the 6 week post-operative time point ] [ Designated as safety issue: No ]
  to determine whether Kneehab XP leads to earlier recovery (measured at the 6 week post-operative time point) when compared to a control group in patients undergoing total knee arthroplasty.
• Visual Analogue Scales [ Time Frame: 1 wk pre-operatively,3,6,12 and 52 post operatively ] [ Designated as safety issue: No ]
  Pain change score
• Stair Climb Test [ Time Frame: 1 wk pre-operatively, 3,6,12,52 week post operatively ] [ Designated as safety issue: No ]
  Change in scores of physical performance measures
• Timed to get up and go [ Time Frame: 1 wk pre-operatively, 3,6,12,52 week post operatively ] [ Designated as safety issue: No ]
  Change in scores of physical performance measures
• Range of Motion [ Time Frame: 1 wk pre-operatively, 3,6,12,52 week post operatively ] [ Designated as safety issue: No ]
  Change in scores of functional and physical performance scores
• Questionnaires [ Time Frame: 1 wk pre-operatively, 3,6,12,52 week post operatively ] [ Designated as safety issue: No ]
  Change in scores in patient outcome measures, functional measures and physical performance measures
• Physical Therapy sessions [ Time Frame: 1 wk pre-operatively, 3,6,12,52 week post operatively ] [ Designated as safety issue: No ]
  Change in patient functional measures and number of therapy sessions required.

The study is a double-blind randomized controlled clinical trial.Approximately 118 patients (males and females) who are at least 40 years of age, who are scheduled for total-knee arthroplasty (TKA) surgery will be randomized into 1) a treatment group who receive Kneehab XP and a standard rehabilitation program and 2) a control group who receive only a sham device and a standard rehabilitation program. Patients are tracked for measures of function, pain, quality of life, physical performance and acceptable states status at 6 weeks and 1 week before surgery and 3, 6, 12, and 52 weeks following surgery.

Hypothesis 1: The effect of 12-weeks of Kneehab XP (peri-operative NMES) combined with standard rehabilitation in patients undergoing TKA surgery will lead to increased quadriceps strength compared to a control group at the 6 week post-operative time point.

Hypothesis 2: The effect of 12-weeks of Kneehab XP (peri-operative NMES) combined with standard rehabilitation in patients undergoing TKA surgery is better than the control group as measured by PASS at post-operative week 6. The investigators hypothesize that a significantly larger proportion of patients will indicate a positive PASS in the Kneehab XP group compared to the control group.

Hypothesis 2:The investigators hypothesize that the mean change scores for pain, physical and functional performance measures will be significantly better for the Kneehab XP group at post operative week 6. Additionally, the investigators report the baseline corrected scores for these outcomes, as well as the primary and secondary outcomes, at all the other follow up time points.

• Device: Kneehab XP
  NMES using Kneehab XP on the affected leg,20 minutes, twice per day, 5 days a week. Subjects will begin use of the device at 6 weeks pre-operatively and continue through 6 weeks post-operatively
• Device: quadriceps TENS (at a minimal sensory input) using Kneehab XP
  on the affected leg, 20 minutes, twice per days, 5 days a week. Subjects will begin use of the device at 6 weeks pre-operatively and continue through 6 weeks post-operatively.

• quadriceps NMES using Kneehab XP
  All subjects in the treatment group will receive quadriceps NMES using Kneehab XP on the affected leg, 20 minutes, twice per day, 5 days a week. Subjects will begin use of the device at 6 weeks pre-operatively and continue through 6 weeks post-operatively.group will also complete the standard TKA post-surgery rehabilitation program used at the Hawkins Foundation
  Intervention: Device: Kneehab XP
• Sham Comparator: quadriceps TENS
  The sham device will look identical to the Kneehab XP device. All subjects in the control group will receive quadriceps TENS (at a minimal sensory input) using Kneehab XP on the affected leg, 20 minutes, twice per days, 5 days a week. Subjects will begin use of the device at 6 weeks pre-operatively and continue through 6 weeks post-operatively.group will also complete the standard TKA post-surgery rehabilitation program used at the Hawkins Foundation
  Intervention: Device: quadriceps TENS (at a minimal sensory input) using Kneehab XP

Inclusion Criteria:

• Individuals who are scheduled for Total Knee Replacement surgery with the Smith and Nephew Visionaire prosthesis and the anterior surgical approach.
• Individuals who are at least 40 years of age.
• Individuals with a body mass index (BMI) <40 kg/ m2
• Individuals who are walking independently with or without assistive devices.
• Individuals with a Short Performance Battery Score greater than 7.
• Must be able and willing to complete all study assessments and to be followed for the full course of the study.
• Must be able to read, write and follow instructions in English.
• Must be able and willing to provide informed consent.
• Must be willing and able to attend the additional pre-operative assessment.

Exclusion Criteria:

• Individuals with a history of foot and/or ankle pathology.
• Individuals with a history of tibial or femoral fractures.
• Individuals with a history of any underlying neurological conditions.
• Individuals with physical conditions which would make them unable to perform study procedures.
• Individuals with a total hip replacement.
• Individuals undergoing revision TKA of the same operated leg.
• Individuals who are pregnant.
• Individuals diagnosed with a medical condition that would contraindicate treatment with the product, e.g. skin lesions at electrode site.
• Individuals with an active implanted medical device (i.e. pacemaker, pump)
• Individuals with a history of stroke
• Individuals with a history of neurological disorder that affects lower extremity function (stroke, peripheral neuropathy, Parkinson's disease, multiple sclerosis, etc.)
• Individuals with a diagnosis of inflammatory arthritis (Rheumatoid arthritis, gout or psoriatic arthritis).
• Individuals with muscle diseases (i.e. muscular dystrophy)
• Individuals with visible skin injury or disease on their legs.
• Individuals who have been committed to an institution by virtue of an order issued either by the courts or by an authority.