Trial Outcomes & Findings for Evaluation of Electrical Nerve Stimulation (TENS) Therapy for Pain Relief Following Total Knee Arthroplasty (TKA) (NCT NCT01641471)

Results Overview

Morphine Equivalent dose, mg/kg

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

116 participants

Primary outcome timeframe

Through 6 weeks after surgery

Results posted on

2018-03-07

Participant Flow

Participant milestones

Participant milestones
Measure	Active TENS Active TENS in combination with a femoral nerve catheter. Patients will begin using the TENS unit immediately following surgery and continuing throughout the 6 weeks postoperatively. EMPI Select TENS: The unit is capable of 0-60 milliamps of output current. The 4 electrodes will be focused on the posterior aspect of the knee during the immediate postoperative period and lasting through discharge from the hospital. Once the patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes off, as needed. Amount of TENS usage and average intensity used will be recorded. An assessment of blinding will be conducted at the conclusion of the study by asking patients what treatment arm they think that they received.	Placebo TENS Placebo TENS in combination with a femoral nerve catheter. Patients will begin using a sham TENS unit (appears identical to Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation) immediately following surgery and continuing throughout the 6 weeks postoperatively. Placebo EMPI Select TENS: Sham unit appears identical to the Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation (even though screen shows 0-60 milliamps of output current). The 4 electrodes will be focused on the posterior aspect of the knee during immediate postoperative period and lasting through discharge from the hospital. Once patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes
Overall Study STARTED	58	58
Overall Study COMPLETED	35	31
Overall Study NOT COMPLETED	23	27

Reasons for withdrawal

Reasons for withdrawal
Measure	Active TENS Active TENS in combination with a femoral nerve catheter. Patients will begin using the TENS unit immediately following surgery and continuing throughout the 6 weeks postoperatively. EMPI Select TENS: The unit is capable of 0-60 milliamps of output current. The 4 electrodes will be focused on the posterior aspect of the knee during the immediate postoperative period and lasting through discharge from the hospital. Once the patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes off, as needed. Amount of TENS usage and average intensity used will be recorded. An assessment of blinding will be conducted at the conclusion of the study by asking patients what treatment arm they think that they received.	Placebo TENS Placebo TENS in combination with a femoral nerve catheter. Patients will begin using a sham TENS unit (appears identical to Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation) immediately following surgery and continuing throughout the 6 weeks postoperatively. Placebo EMPI Select TENS: Sham unit appears identical to the Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation (even though screen shows 0-60 milliamps of output current). The 4 electrodes will be focused on the posterior aspect of the knee during immediate postoperative period and lasting through discharge from the hospital. Once patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes
Overall Study Withdrawal by Subject	19	19
Overall Study Lost to Follow-up	2	4
Overall Study Protocol Violation	2	4

Baseline Characteristics

Evaluation of Electrical Nerve Stimulation (TENS) Therapy for Pain Relief Following Total Knee Arthroplasty (TKA)

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Active TENS n=35 Participants Active TENS in combination with a femoral nerve catheter. Patients will begin using the TENS unit immediately following surgery and continuing throughout the 6 weeks postoperatively. EMPI Select TENS: The unit is capable of 0-60 milliamps of output current. The 4 electrodes will be focused on the posterior aspect of the knee during the immediate postoperative period and lasting through discharge from the hospital. Once the patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes off, as needed. Amount of TENS usage and average intensity used will be recorded. An assessment of blinding will be conducted at the conclusion of the study by asking patients what treatment arm they think that they received.	Placebo TENS n=31 Participants Placebo TENS in combination with a femoral nerve catheter. Patients will begin using a sham TENS unit (appears identical to Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation) immediately following surgery and continuing throughout the 6 weeks postoperatively. Placebo EMPI Select TENS: Sham unit appears identical to the Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation (even though screen shows 0-60 milliamps of output current). The 4 electrodes will be focused on the posterior aspect of the knee during immediate postoperative period and lasting through discharge from the hospital. Once patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes	Total n=66 Participants Total of all reporting groups
Age, Continuous	67.3 years STANDARD_DEVIATION 3.7 • n=5 Participants	60.3 years STANDARD_DEVIATION 7.7 • n=7 Participants	62.8 years STANDARD_DEVIATION 8.6 • n=5 Participants
Sex: Female, Male Female	14 Participants n=5 Participants	16 Participants n=7 Participants	30 Participants n=5 Participants
Sex: Female, Male Male	21 Participants n=5 Participants	15 Participants n=7 Participants	36 Participants n=5 Participants

PRIMARY outcome

Timeframe: Through 6 weeks after surgery

Morphine Equivalent dose, mg/kg

Outcome measures

Outcome measures
Measure	Active TENS n=35 Participants Active TENS in combination with a femoral nerve catheter. Patients will begin using the TENS unit immediately following surgery and continuing throughout the 6 weeks postoperatively. EMPI Select TENS: The unit is capable of 0-60 milliamps of output current. The 4 electrodes will be focused on the posterior aspect of the knee during the immediate postoperative period and lasting through discharge from the hospital. Once the patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes off, as needed. Amount of TENS usage and average intensity used will be recorded. An assessment of blinding will be conducted at the conclusion of the study by asking patients what treatment arm they think that they received.	Placebo TENS n=31 Participants Placebo TENS in combination with a femoral nerve catheter. Patients will begin using a sham TENS unit (appears identical to Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation) immediately following surgery and continuing throughout the 6 weeks postoperatively. Placebo EMPI Select TENS: Sham unit appears identical to the Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation (even though screen shows 0-60 milliamps of output current). The 4 electrodes will be focused on the posterior aspect of the knee during immediate postoperative period and lasting through discharge from the hospital. Once patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes
Narcotic Usage	997.7 morphine equivalents Standard Deviation 1124.9	1025.8 morphine equivalents Standard Deviation 1053.6

SECONDARY outcome

Timeframe: 6 weeks (+/- 3 days) postoperative

Pain VAS is a continuous scale comprised of a vertical line, 10 centimeters in length, with each centimeter marked by its' corresponding whole number (1, 2, 3, etc.). It ranges from 0 to 10, with 0 being no pain and 10 being maximum pain.

Outcome measures

Outcome measures
Measure	Active TENS n=35 Participants Active TENS in combination with a femoral nerve catheter. Patients will begin using the TENS unit immediately following surgery and continuing throughout the 6 weeks postoperatively. EMPI Select TENS: The unit is capable of 0-60 milliamps of output current. The 4 electrodes will be focused on the posterior aspect of the knee during the immediate postoperative period and lasting through discharge from the hospital. Once the patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes off, as needed. Amount of TENS usage and average intensity used will be recorded. An assessment of blinding will be conducted at the conclusion of the study by asking patients what treatment arm they think that they received.	Placebo TENS n=31 Participants Placebo TENS in combination with a femoral nerve catheter. Patients will begin using a sham TENS unit (appears identical to Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation) immediately following surgery and continuing throughout the 6 weeks postoperatively. Placebo EMPI Select TENS: Sham unit appears identical to the Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation (even though screen shows 0-60 milliamps of output current). The 4 electrodes will be focused on the posterior aspect of the knee during immediate postoperative period and lasting through discharge from the hospital. Once patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes
Visual Analog Pain Score (VAS)	1.57 units on a scale Standard Deviation 1.35	1.54 units on a scale Standard Deviation 1.52

SECONDARY outcome

Timeframe: 6 weeks (+/- 3 days) postoperative

Timed up and go (TUG) test. These methods follows those published by Podsiadlo and Richardson, JAGS 1991; 39:142-148, in which the patient is observed and timed while he/she rises from an arm chair, walks 3 meters, turns, walks back, and sits down again.

Outcome measures

Outcome measures
Measure	Active TENS n=35 Participants Active TENS in combination with a femoral nerve catheter. Patients will begin using the TENS unit immediately following surgery and continuing throughout the 6 weeks postoperatively. EMPI Select TENS: The unit is capable of 0-60 milliamps of output current. The 4 electrodes will be focused on the posterior aspect of the knee during the immediate postoperative period and lasting through discharge from the hospital. Once the patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes off, as needed. Amount of TENS usage and average intensity used will be recorded. An assessment of blinding will be conducted at the conclusion of the study by asking patients what treatment arm they think that they received.	Placebo TENS n=31 Participants Placebo TENS in combination with a femoral nerve catheter. Patients will begin using a sham TENS unit (appears identical to Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation) immediately following surgery and continuing throughout the 6 weeks postoperatively. Placebo EMPI Select TENS: Sham unit appears identical to the Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation (even though screen shows 0-60 milliamps of output current). The 4 electrodes will be focused on the posterior aspect of the knee during immediate postoperative period and lasting through discharge from the hospital. Once patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes
Functional Assessments	9.31 seconds Standard Deviation 2.67	10.39 seconds Standard Deviation 4.29

SECONDARY outcome

Timeframe: 6 weeks (+/- 3 days) postoperative

Physical Component Score. Physical Component Score (PCS) are computed using the scores of twelve questions and range from 0 to 100, where a zero score indicates the lowest level of health measured by the scales and 100 indicates the highest level of health. PCS provides emphasis on questions about general health, physical functioning and role playing and bodily pain. PCS is standardized using a z-score transformation and normed to a US population (Based on a 1990 norm) of a score of 50.0 and a standard deviation of 10.0. Normalized scores reported.

Outcome measures

Outcome measures
Measure	Active TENS n=35 Participants Active TENS in combination with a femoral nerve catheter. Patients will begin using the TENS unit immediately following surgery and continuing throughout the 6 weeks postoperatively. EMPI Select TENS: The unit is capable of 0-60 milliamps of output current. The 4 electrodes will be focused on the posterior aspect of the knee during the immediate postoperative period and lasting through discharge from the hospital. Once the patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes off, as needed. Amount of TENS usage and average intensity used will be recorded. An assessment of blinding will be conducted at the conclusion of the study by asking patients what treatment arm they think that they received.	Placebo TENS n=31 Participants Placebo TENS in combination with a femoral nerve catheter. Patients will begin using a sham TENS unit (appears identical to Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation) immediately following surgery and continuing throughout the 6 weeks postoperatively. Placebo EMPI Select TENS: Sham unit appears identical to the Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation (even though screen shows 0-60 milliamps of output current). The 4 electrodes will be focused on the posterior aspect of the knee during immediate postoperative period and lasting through discharge from the hospital. Once patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes
General Health Outcome - SF-12 Physical Component Summary	33.57 z-scale Standard Deviation 7.02	31.78 z-scale Standard Deviation 7.07

Adverse Events

Active TENS

Serious events: 1 serious events

Other events: 10 other events

Deaths: 0 deaths

Placebo TENS

Serious events: 2 serious events

Other events: 9 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Active TENS n=35 participants at risk Active TENS in combination with a femoral nerve catheter. Patients will begin using the TENS unit immediately following surgery and continuing throughout the 6 weeks postoperatively. EMPI Select TENS: The unit is capable of 0-60 milliamps of output current. The 4 electrodes will be focused on the posterior aspect of the knee during the immediate postoperative period and lasting through discharge from the hospital. Once the patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes off, as needed. Amount of TENS usage and average intensity used will be recorded. An assessment of blinding will be conducted at the conclusion of the study by asking patients what treatment arm they think that they received.	Placebo TENS n=31 participants at risk Placebo TENS in combination with a femoral nerve catheter. Patients will begin using a sham TENS unit (appears identical to Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation) immediately following surgery and continuing throughout the 6 weeks postoperatively. Placebo EMPI Select TENS: Sham unit appears identical to the Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation (even though screen shows 0-60 milliamps of output current). The 4 electrodes will be focused on the posterior aspect of the knee during immediate postoperative period and lasting through discharge from the hospital. Once patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes
Infections and infestations Infection	2.9% 1/35 • Number of events 1	3.2% 1/31 • Number of events 1
Nervous system disorders Delirium	0.00% 0/35	3.2% 1/31 • Number of events 1

Other adverse events

Other adverse events
Measure	Active TENS n=35 participants at risk Active TENS in combination with a femoral nerve catheter. Patients will begin using the TENS unit immediately following surgery and continuing throughout the 6 weeks postoperatively. EMPI Select TENS: The unit is capable of 0-60 milliamps of output current. The 4 electrodes will be focused on the posterior aspect of the knee during the immediate postoperative period and lasting through discharge from the hospital. Once the patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes off, as needed. Amount of TENS usage and average intensity used will be recorded. An assessment of blinding will be conducted at the conclusion of the study by asking patients what treatment arm they think that they received.	Placebo TENS n=31 participants at risk Placebo TENS in combination with a femoral nerve catheter. Patients will begin using a sham TENS unit (appears identical to Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation) immediately following surgery and continuing throughout the 6 weeks postoperatively. Placebo EMPI Select TENS: Sham unit appears identical to the Active TENS unit, yet is created to deliver low-level, non-therapeutic electrical stimulation (even though screen shows 0-60 milliamps of output current). The 4 electrodes will be focused on the posterior aspect of the knee during immediate postoperative period and lasting through discharge from the hospital. Once patient is discharged, he/she will be instructed to use the device as he/she would like, whether it is a continuation of the posterior placement of the electrodes, or a more traditional anterior criss-cross positioning. Patients will be instructed to use the device for 2 hours on, followed by 30 minutes
Skin and subcutaneous tissue disorders Blisters	14.3% 5/35 • Number of events 5	16.1% 5/31 • Number of events 5
Musculoskeletal and connective tissue disorders Swelling	2.9% 1/35 • Number of events 1	3.2% 1/31 • Number of events 1
Musculoskeletal and connective tissue disorders Intraoperative MCL tear	0.00% 0/35	3.2% 1/31 • Number of events 1
Musculoskeletal and connective tissue disorders Postoperative ligament tear	0.00% 0/35	3.2% 1/31 • Number of events 1
Respiratory, thoracic and mediastinal disorders Pulmonary edema	2.9% 1/35 • Number of events 1	0.00% 0/31
Skin and subcutaneous tissue disorders Rash	5.7% 2/35 • Number of events 2	0.00% 0/31
Surgical and medical procedures Wound drainage	2.9% 1/35 • Number of events 1	3.2% 1/31 • Number of events 1

Additional Information

Research Program Manager

Cleveland Clinic - Section of Adult Reconstrution

Phone: 216-444-4954

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place