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Chronic PainNCT01117870

Assess the Effectiveness of Pulse RadioFrequency in Patients With Chronic Lumbar Radicular Pain

A study testing Pulsed Radiofrequency in people with Chronic Pain and Back Pain, run by McMaster University at 1 site in Canada.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Pulsed RadioFrequency (PRF) is a relatively new technique derived from a well established and proven intervention, thermal radiofrequency (RF). Both procedures are used in the treatment of chronic pain. Unlike RF treatment, PRF does no direct damage to the nerve. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Chronic Pain, Back Pain
What is being tested?
Pulsed Radiofrequency
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
31 participants
Where
1 siteCanada
Study dates
Jul 2010to Nov 2012
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • > 18 years of age
  • CLR for at least 4 months of more, with concordant findings on either MRI and CT scan
  • VAS score of at least 60/100 at presentation
  • informed consent

Who cannot join

  • < 18 years of age
  • patient refusal
  • any contraindication to neuraxial injection such as coagulation disturbance, anticoagulant therapy, bleeding disorder, or infection at site of injection
  • anatomical deformity or derangement, either congenital or surgical such as: extreme scoliosis, previous implant or instrumentation making it difficult to access the foramen as evidence by MRI, CT, or plain x-rays
  • uncontrolled diabetes or severe coronary vascular disease necessitating continuation of anticoagulation therapy
  • known history of psychiatric illness-such as depression or psychosis
Show all 10Show fewer
  • presence of cancer accounting for present symptoms
  • patient's inability of communicate in English and inability to understand and fill out the required follow-up questionnaire and form
  • allergy to local anesthetics or steroid or contrast medium
  • any patient with a history of acute neurological weakness or neurodeficit in the affected limb in terms of measurable motor weakness or abnormal reflexes

Trial locations and contacts

1 site in 1 country.

Canada1 site
  • East End Clinic, St. Joseph's Healthcare Hamilton

    Hamilton, Ontario, L8N 4A6

Other trials in Canada

About this study

Official title: Randomized, Placebo Controlled, Double-blinded Trial to Assess the Effectiveness of Pulse RadioFrequency Treatment of Dorsal Root Ganglion in Patients With Chronic Lumbar Radicular Pain

Pulsed RadioFrequency (PRF) is a relatively new technique derived from a well established and proven intervention, thermal radiofrequency (RF). Both procedures are used in the treatment of chronic pain. Unlike RF treatment, PRF does no direct damage to the nerve. During PRF treatment, electrical energy is applied with a small needle to the affected nerve using a pulsed time cycle that delivers short bursts of RF current. This study is interested in looking at the efficacy of PRF for chronic lumbar radicular pain (CLR) and to assess whether a larger scale clinical study with the same methods can be used.

Read the detailed description

Methodology and Techniques:

Patients would be screened at St Joseph-East End Pain Clinic for Chronic Lumbar Radiculopathy (CLR) of at least 4 months duration. Based on the history and clinical examination, a diagnosis of CLR involving one or more spinal segments is made and noted. The patient is considered eligible for the study if a CT or MRI of lumbar spine done within the last 4 months demonstrates pathology that is concordant with the patient's clinical symptoms. The spinal level(s) targeted for treatment will be based on clinical findings, e.g. if a patient exhibits signs and symptoms of right L4 radiculopathy, and the MRI demonstrates right paracentral disc herniations at both L4-5 and L5-S1, only the L4 DRG will be targeted.

Patients fulfilling the inclusion criteria will be fully explained about the nature of study, interventions involved and the possible complications after which an informed consent will be taken. Enrolled patients would be randomized-according to the method chosen and included in the study according to previously randomized order. He/she will also meet the ASSESSOR (blind to intervention)-who would note down the baseline parameters of the patient and also collect a baseline Oswestry Score chart, along with noting down other parameters.

A patient having bilateral radiculopathy will be treated for his most affected side in the trial. A patient having CLR of more than one segment on one side shall be treated for all the involved segments with the same technique and counted as a single procedure or intervention for the study.

All OR (operating room) personnel, including the physician performing intervention and patient shall be blind to the randomization and treatment. The grouping code, hence the actual treatment will only be known by the person operating the RF machine.

Only the RF technician shall be in view of the working details of the RF machine and the noise of the machine is cut off. This ensures blinding of all involved except the RF technician. After checking for informed consent and other safety checklist, patient will only be revealed as belonging to group A or B.

All interventions will be done as day care procedures in the OR. Patients would continue to use their medications as before. If the pain relief obtained necessitates decrease in the usage of medications that shall be recorded. Similarly unsatisfactory pain relief obtained necessitating increase in the dose or change of medications shall be recorded. The other parameters to be used for statistical analysis are collected as mentioned in the data analysis paragraph.

The patient will have an established IV access. He would be put in prone position. The involved area of back would be made sterile using chlorohexidine 2% and draped. The patient would be connected to continuous monitoring of 3 lead ECG, NIBP (Non-Invasive Blood Pressure) and pulse oximetry. Sedation, if used will be minimal (Grade I or II) to obtain the necessary response of the patient. Under fluoroscopy guidance- particular spinal segment(s) affected is (are) identified and confirmed. LA using 2% lidocaine is infiltrated to the skin at entry site. For both groups a RF needle (Bayliss: 22-G needle, 5-mm curved active tip and 10 cm) is used. With an appropriate fluoroscopy view needle is inserted to the target location in both the groups.

Target location: the DRG which is an enlargement formed by the dorsal nerve root just proximal to its junction with the spinal nerve lies within the dural sleeve and occupies the upper, medial part of the intervertebral foramen (22). It is confirmed with an anteroposterior fluoroscopy view in which it is advanced, if required, until the tip is located one-third to halfway into the pedicle column (18).

Target Confirmation (Malik et al): Appropriate fluoroscopic placement of needle-near DRG at the lumbar area is noted; on anteroposterior x-ray projection, the DRG is described to lie immediately behind the lateral aspect of the facet column at all spinal levels and on lateral x-ray projection, it is localized to the dorsocranial quadrant of the IVF (intervertebral foramen) Proximity of the needle to the DRG is determined by appropriate sensory stimulation with 50 Hz, at more than 0.4 V (avoids intraganglionic placement) and less than or equal to 0.6 V; motor stimulation at 2 Hz with threshold 1.5-2 times greater than sensory threshold to avoid placement near the anterior nerve root. A radiculogram done also confirms the appropriate placement and helps recognise intradural placement of the needle.

Both the groups will have their respective DRG stimulated for sensory confirmation.

Treatment: Once positioned the physician shall indicate to the RF technician as "treatment" only, at which time either PRF or placebo (only continuing sensory stimulation at a low frequency is applied), without revealing.

Application of Intervention: In Group A-PRF; PRF would be applied for 120 seconds at 42 degree centigrade. Group B-placebo; the needle would be continuously stimulated at a low voltage to give a sensation of PRF application and also to obtain the necessary noise to blind the patients.

Only lidocaine 1% 0.5 ml shall be given in both groups before carrying out the treatment.

In both groups the same procedure is done at all the involved spinal segmental levels. After the procedure the patient is shifted to recovery area to be monitored, observed and managed for any side effects. The observer, blind to the interventions, will record the pain scores and also check for side effects observed before the patient is discharged home.

Blinding and Bias control In our study we plan to blind the patient, the treating physician and the assessor for the actual intervention being done. The randomization code, hence the actual treatment will only be known and administered by the person operating the RF machine. The randomization will be concealed in sealed envelopes

Blinding of patients will be achieved by:

Randomization: Patients will be randomly allocated to each group using a 1:1 ratio. The allocation will be blocked using block sizes of 2, 4, 6.

Both interventions will be similarly, including the use of fluoroscopy. Both interventions will be done using the same kind of needle and technique of stimulation.

Patients belonging to placebo group will have a continuous low voltage stimulation to mask the effect of "no intervention".

Blinding of assessor will be achieved by:

Will not know the randomization order, Will not be present during the intervention, Will not be able to access any written or dictated notes regarding the intervention.

Blinding of the treating Physician will be achieved by:

Will not know the randomization order or grouping of patients, Will not be revealed the treatment applied.

Duration of treatment period Treatment intervention period will involve approximately 30 mins to 60 mins of actual intervention done in the OR.

Duration and Frequency of follow up The duration of follow up will be 3 months after the intervention. The frequency of follow up will be as follows,

The patient would be assessed post-intervention on the following days:

  1. 30 minutes post-procedure in recovery
  2. 24 hrs after-by a phone call (only VAS and side effects)
  3. At 1 week post-procedure-Visit to Observer (VAS, ODI, medications, side effects)
  4. At 4 weeks post-procedure-Visit to Observer -assessment for success (VAS, ODI, medications, side effects).
  5. At 2 months post-procedure-Visit to Observer (VAS, ODI, medications, side effects)
  6. At 3 months post -procedure-Visit to Observer-last follow up visit (VAS, ODI, medications, side effects)

Sample Size, Recruitment Rate:

Sample size has been determined based on feasibility considerations. Total duration of recruitment planned is 8 months The proposed target is recruitment for 8 months, with an expectation of 4 patients/month, making a total of 32 patients for the study.

Potential to recruit patients, as 4 patients every month has been calculated based on the TransForaminal Steroid Injections (TFESI) performed in the last 3-6 months and also booked for the next 3-6 months (calculated as monthly) at St Joseph's Healthcare; data obtained from St Joseph's Healthcare Department of Anesthesia and Pain Dept Secretary Office.

TFESI represents a well accepted, presently performed intervention for patients of CLR and most patients suitable for that are potential recruits for this study.

Statistical Tests The Characteristics of the trial participants will be described using mean (standard deviation) or counts as appropriate. We will use a flow diagram to summarize the flow of patients in the trial.

Feasibility outcomes will be reported as counts (proportions).

Duration of The Trial The proposed study would only recruit patients for 8 months and compare with the expected estimation of the recruitment.

Being tested
Pulsed Radiofrequency, Placebo
Keywords
chronic, pain, lumbar, Radicular
Medical subject headings
Chronic Pain, Back Pain, Bronchiolitis Obliterans Syndrome, Pain

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Pulsed RadiofrequencyOther

    120 seconds at 42 degrees celsius

  • PlaceboOther

    Needle will be continuously stimulated at a low voltage to give a sensation of PRF application.

Study groups in NCT01117870
Study groupRoleWhat they receive
PlaceboPlacebo comparatorThe needle will be continuously stimulated at a low voltage to give a sensation of PRF treatment.
Receives: Other: Placebo
Pulsed RadiofrequencyExperimentalPRF will be applied for 120 seconds at 42 degrees celsius.
Receives: Other: Pulsed Radiofrequency

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Recruitment Rate

    Expected recruitment is at least 4 patients per month. At least 80% of eligible patients fulfilling the selection criteria can be recruited. The final assessment was at the end of 15 months, at which time all the subjects were enrolled. Participants withdrawing within 4 weeks after the interventional shall not be included in the study. However participants withdrawing after 4 weeks of the intervention shall be included in the final analysis, on intention to treat principle.

    Measured: 15 month point

  2. Number of Participants Lost to Follow-up at 3 Months

    Patients who were lost to follow-up at 3 months were recorded.

    Measured: 3 months

Secondary outcomes (4)
  1. Change in Mean Visual Analogue Scale (VAS) Scores From Baseline to 4 Weeks

    Secondary outcomes were considered as exploratory. Is PRF an effective treatment for patients with CLR pain? It will be measured by a change in VAS scores from baseline measurement at recruitment.

    Visual analog scale (VAS) - For pain intensity, the scale is most commonly anchored by "no pain" (score of 0) and "pain as bad as it could be" or "worst imaginable pain" (score of 10) on a 10-cm scale.

    Measured: baseline (at recruitment) and at 4 Weeks

  2. Assessment of Side Effects

    Percentage of patients having side effects after PRF treatment assessed at 1 week compared to placebo group. Assessment of persisting side effects, percentage of patients having side effects after PRF treatment beyond 1 week compared to the placebo group. Side effects could be nausea, headache, momentary increase in pain, fever, tingling, itching, and/or burning skin at point of treatment

    Measured: 1 week and up to 3 months

  3. Change in Oswestry Disability Index (ODI) From Baseline to 4 Week

    ODI is an index derived from the Oswestry Low Back Pain Questionnaire used to quantify disability for low back pain. The self-completed questionnaire contains ten topics concerning intensity of pain, lifting, ability to: care for oneself, walk, sit, sexual function, stand, social life, sleep quality, and ability to travel. Each topic category is followed by 6 statements describing different potential scenarios in the patient's life relating to the topic. The patient then checks the statement which most closely resembles their situation. Each question is scored on a scale of 0-5 with the first statement being zero and indicating the least amount of disability and the last statement is scored 5 indicating most severe disability.The scores for all questions answered are summed, then multiplied by two to obtain the index (range 0 to 100). Zero is equated with no disability and 100 is the maximum disability possible.

    Measured: baseline (at recruitment) and at 4 weeks

  4. Number of Participants Who Discontinued Analgesics After Intervention

    Number of PRF treatment patients with increase or decrease in medication use (either in dose, frequency, or no use), compared with the placebo group.

    Measured: 4 weeks

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted6 May 2010 (estimated)
  2. Study startJul 2010
  3. Primary completionJun 2012
  4. Study completionNov 2012

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
31 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT01117870
Sponsor's protocol ID
PRF-1
Status last verified
Aug 2026
First submitted
4 May 2010
Last updated
28 Aug 2026
Data monitoring committee
No
Individual data sharing
No

Publications

  • Shanthanna H, Chan P, McChesney J, Paul J, Thabane L. Assessing the effectiveness of 'pulse radiofrequency treatment of dorsal root ganglion' in patients with chronic lumbar radicular pain: study protocol for a randomized control trial. Trials. 2012 Apr 28;13:52. doi: 10.1186/1745-6215-13-52.

    PubMed 22540851

Questions about this trial

What is this clinical trial studying?

A study testing Pulsed Radiofrequency in people with Chronic Pain and Back Pain, run by McMaster University at 1 site in Canada.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 28 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

Yes. Results are posted in the registry (first posted 21 Mar 2017). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Recruitment Rate (time frame: 15 month point). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT01117870, which also lists 1 linked publication.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Aug 2026.

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