Low Back Pain
Conditions
Keywords
Chronic Low Back Pain, Lower Extremity Pain, Central Sensitization, Percutaneous Neuromodulation Therapy
Brief summary
The purpose of this study is to assess the benefits of Percutaneous Neuromodulation Therapy when compared to a reference sham treatment in the treatment of patients who have undergone surgical intervention for chronic low back pain with or without a radiating lower extremity pain component.
Interventions
DEVICEVertis Percutaneous Neuromodulation Therapy (PNT)
* Ten PNT sessions in eleven weeks * On average, one PNT session per week * Ten lumbar Safeguide electrodes (three centimeters in length) deployed per lumbar montage * Forty-five minutes of electrical stimulation for each session * Electrical stimulation parameters: * Continuous 50 Hz current * Charge-balanced, biphasic (each phase is 200 microsec), rectangular waveform * Intensity to subject's tolerance for ten minutes then increased to a mildly uncomfortable level
DEVICETranscutaneous Electrical Nerve Stimulation (TENS)
* Ten TENS sessions in eleven weeks * On average, one TENS session per week * Four 2-inch (5.1 centimeters) diameter pads applied per TENS lumbar montage * Forty-five minutes of electrical stimulation for each session * Electrical stimulation parameters: * Current at 2 Hz-low frequency * Pulse trains delivered as asymmetric, biphasic, square waveform current, with pulse width lasting 20 microsec * Intensity titrated according to subject's sensory threshold * To maintain blinding, the treating physician or clinician will check on the subject after 10 minutes and dial the channels down just prior to the point of turning off the device.
Sponsors
RS Medical
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Low back pain for at least 6 months * If lower extremity pain present, must be present for at least 3 months * Visual analog scale (VAS) score for low back pain at least 50 out of 100 * Lumbar or lumbosacral surgical intervention without pain relief * Central sensitization symptoms * Agrees to follow randomized treatment plan * 18 years of age or older * Signed informed consent form
Exclusion criteria
* Significant change to low back or lower extremity pain within 4 weeks prior to enrollment * Nociceptive and/or neuropathic pain symptoms in the spine due to structural and/or mechanical instabilities * Three or more lumbar or lumbosacral surgical interventions; one or more surgical interventions in areas other than lumbar or lumbosacral spine * Three or more lumbar vertebral segments fused * Lumbar or lumbosacral surgical intervention in last 9 months; areas other than lumbar or lumbosacral in last 12 months * Any additional surgical intervention required 3 months post-enrollment * Symptoms consistent with sympathetically-maintained pain * Evidence of serious neurological deficits or impairments * Significant changes in pain medications within 4 weeks prior to enrollment * Psychosocial issues that conflict with valid reporting by patient * Prior treatment with percutaneous electrical stimulation or sensitivity to electrical stimulation * Current use of another electrical stimulation device for low back or lower extremity pain * Current enrollment in another clinical trial within the last 30 days * Current or prior malignancy or cancer * Serious or uncontrolled systemic illness * Body mass index (BMI) greater than 40 * Pregnant or intends to become pregnant during the study * Implanted medical device * Relationship with study staff * Unable to attend study office visits or complete study measures
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change From Baseline in Time-averaged Pain Intensity Visual Analog Scale (VAS) Score | Time-averaged from the first available observation to the last available observation (12 months for completed subjects) | Visual analog scale (VAS) for pain (100mm line with 0/No pain on the left and 100/Worst pain imaginable on the right). Subjects drew vertical line to indicate pain. Time-averaged method accounts for time between visits by dividing area beneath the score curve by time between first and last available visits. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Total Expenditure Per Day on All Lower Back Pain Related Interventions | Baseline, Month 01, Month 02, Month 04, Month 06, Month 08, Month 10, Month 12 | Expenditures were assessed by patient report at each visit. Interventions were coded to Current Procedural Terminology (CPT) 2008; costs were derived from Medicare, Managed Care, and Workers' Comp fees. Costs for providers assume 30 minutes at returning patient rate. Drug costs were coded to a dictionary extrapolated from 2008 market prices. |
Countries
United States
Participant flow
Participants by arm
| Arm | Count |
|---|---|
| Percutaneous Neuromodulation Therapy (PNT) Active/test group receiving 10 Percutaneous Neuromodulation Therapy (PNT) sessions of 45 minutes each over 11 weeks. PNT delivers 50 Hz current in a charge-balanced, biphasic, rectangular waveform. | 57 |
| Transcutaneous Electrical Nerve Stimulation (TENS) Sham comparator group receiving 10 TENS sessions of 45 minutes each over 11 weeks. Delivered 2 Hz pulse trains as asymmetric, biphasic, square waves with pulse width of 20 microseconds. | 65 |
| Total | 122 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | Lost to Follow-up | 0 | 1 |
| Overall Study | Study terminated | 27 | 27 |
| Overall Study | Withdrawal by Subject | 15 | 13 |
Baseline characteristics
| Characteristic | Transcutaneous Electrical Nerve Stimulation (TENS) | Percutaneous Neuromodulation Therapy (PNT) | Total |
|---|---|---|---|
| Age Categorical <=18 years | 0 participants | 0 participants | 0 participants |
| Age Categorical >=65 years | 10 participants | 14 participants | 24 participants |
| Age Categorical Between 18 and 65 years | 54 participants | 43 participants | 97 participants |
| Age Continuous | 55.9 years STANDARD_DEVIATION 11 | 53.7 years STANDARD_DEVIATION 15.1 | 54.8 years STANDARD_DEVIATION 13.1 |
| Region of Enrollment United States | 65 participants | 57 participants | 122 participants |
| Sex: Female, Male Female | 37 Participants | 33 Participants | 70 Participants |
| Sex: Female, Male Male | 28 Participants | 24 Participants | 52 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 29 / — | 38 / — |
| serious Total, serious adverse events | 3 / — | 3 / — |
Outcome results
Primary
Change From Baseline in Time-averaged Pain Intensity Visual Analog Scale (VAS) Score
Visual analog scale (VAS) for pain (100mm line with 0/No pain on the left and 100/Worst pain imaginable on the right). Subjects drew vertical line to indicate pain. Time-averaged method accounts for time between visits by dividing area beneath the score curve by time between first and last available visits.
Time frame: Time-averaged from the first available observation to the last available observation (12 months for completed subjects)
Population: Analysis population was intention to treat (ITT), excluding subjects who had no follow-up (after the initial 10-week treatment phase) data available.
| Arm | Measure | Group | Value (LEAST_SQUARES_MEAN) | Dispersion |
|---|---|---|---|---|
| Percutaneous Neuromodulation Therapy (PNT) | Change From Baseline in Time-averaged Pain Intensity Visual Analog Scale (VAS) Score | Back pain | -10.9 mm | Standard Error 3.1 |
| Percutaneous Neuromodulation Therapy (PNT) | Change From Baseline in Time-averaged Pain Intensity Visual Analog Scale (VAS) Score | Radiating leg/buttock pain | -12.8 mm | Standard Error 3.2 |
| Transcutaneous Electrical Nerve Stimulation (TENS) | Change From Baseline in Time-averaged Pain Intensity Visual Analog Scale (VAS) Score | Back pain | -11.7 mm | Standard Error 2.7 |
| Transcutaneous Electrical Nerve Stimulation (TENS) | Change From Baseline in Time-averaged Pain Intensity Visual Analog Scale (VAS) Score | Radiating leg/buttock pain | -9.8 mm | Standard Error 2.9 |
Secondary
Total Expenditure Per Day on All Lower Back Pain Related Interventions
Expenditures were assessed by patient report at each visit. Interventions were coded to Current Procedural Terminology (CPT) 2008; costs were derived from Medicare, Managed Care, and Workers' Comp fees. Costs for providers assume 30 minutes at returning patient rate. Drug costs were coded to a dictionary extrapolated from 2008 market prices.
Time frame: Baseline, Month 01, Month 02, Month 04, Month 06, Month 08, Month 10, Month 12
Population: Analysis population was intention to treat (ITT).
| Arm | Measure | Value (MEDIAN) |
|---|---|---|
| Percutaneous Neuromodulation Therapy (PNT) | Total Expenditure Per Day on All Lower Back Pain Related Interventions | 2.97 Dollars |
| Transcutaneous Electrical Nerve Stimulation (TENS) | Total Expenditure Per Day on All Lower Back Pain Related Interventions | 5.30 Dollars |