Effect of TENS for Pain and Function After Total Knee Replacement

Study Overview
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Brief Summary
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Our primary hypothesis is that TENS decreases pain with movement by reducing hyperalgesia. Minimizing the severe pain experienced during required activities in the immediate postoperative period will promote functional recovery and prevent the development of new chronic pain syndromes.

Official Title
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Effect of TENS on Hyperalgesia, Pain With Movement, and Function After TKR

Conditions
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Unilateral Primary Osteoarthritis of Knee, Primary Osteoarthritis of Knee Nos

Intervention / Treatment
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* Device: Placebo TENS
* Device: Active TENS


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Primary osteoarthritis of the knee Speak English Unilateral total knee replacement Exclusion Criteria: No ambulation, assisted or otherwise Use of TENS by subject in past 5 yrs Current use of TENS by someone else in subject's household Stroke or other condition which seriously impairs sensation in legs or ability to follow directions. Condition that precludes use of TENS (pacemaker, allergy to nickel, etc.) Chronic pain (other than in surgical knee) that is currently being treated or is severe. (Do not exclude for fibromyalgia).

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 100 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
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Active TENS<br>High-frequency intense TENS provided with the EMPI Select TENS. The generator emits a balanced, asymmetrical, biphasic waveform and has buttons for variation of frequency and amplitude. A rate modulation frequency of 50pps and 150pps every 0.5 seconds will be used with a pulse width of 150 microseconds (μs). | Device: Active TENS<br>* High-frequency intense TENS provided with the EMPI Select TENS. The generator emits a balanced, asymmetrical, biphasic waveform and has buttons for variation of frequency and amplitude. A rate modulation frequency of 50pps and 150pps every 0.5 seconds will be used with a pulse width of 150 microseconds (μs).<br>|
| Placebo Comparator: Placebo TENS<br>Subjects randomized to the placebo group will use an EMPI TENS Select device that emits a current for 45 seconds then shuts off. They will be asked when they first feel the current, then the device will be turned down a half-point to provide treatment at a sub-sensory level. This unit displays an active indicator light suggesting to the subject that the unit is actively emitting current. At discharge, subject will be sent home with an adequate supply of batteries and asked to change batteries when the device goes below 4 bars, further suggesting that the device is actively working. | Device: Placebo TENS<br>* Subjects randomized to the placebo group will use an EMPI TENS Select device that emits a current for 45 seconds then shuts off. They will be asked when they first feel the current, then the device will be turned down a half-point to provide treatment at a sub-sensory level. This unit displays an active indicator light suggesting to the subject that the unit is actively emitting current. At discharge, subject will be sent home with an adequate supply of batteries and asked to change batteries when the device goes below 4 bars, further suggesting that the device is actively working.<br>|
| No Intervention: Standard Care<br>Subjects randomized to Standard Care will be given no TENS unit. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Self-Reported Pain With Movement | While subject's knee extension is measured, they report their pain on 0-20 Numeric Rating Scale (where 0 is no pain and 20 is pain as bad as you can imagine). | 1 day post-op | 
| Self-reported Pain With Walking (From Iowa Gait Test) | Subjects are instructed to walk as quickly as they safely can for 15 seconds. Their pain was assessed with a Numeric Rating Scale (where 0 is no pain and 20 is pain as bad as you can imagine). | 2 days post-op | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Knee OA, TENS, Total knee replacement, Knee arthroplasty, total unilateral knee replacement