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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
A Single-Blind, Prospective, Randomised Control Trial Comparing Two Radiofrequency Neurotomy (RFN) Techniques For the Treatment of Chronic Lower Back Pain Originating from Facet Joints
Scientific title
A Single-Blind, Prospective, Randomised Control Trial Comparing Anatomical Thermal Radiofrequency Neurotomy (RFN) of Lumbar Medial Branch Derived Facet Pain to the Generic Radiofrequency Neurotomy Technique.
Secondary ID [1] 294813 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Chronic Lower Back Pain 307743 0
Condition category
Condition code
Neurological 306800 306800 0 0
Other neurological disorders

Study type
Description of intervention(s) / exposure
Radiofrequency Neurotomy (RFN) is a treatment that has been available for many years for facet joint pain following appropriate diagnosis with facet joint injections or medial branch blocks. If facet joints are the sole cause of pain, RFN may provide total pain relief. If they are a contributing cause, partial relief may be provided. The procedure involves applying radiofrequency to the nerve for a short period of time. The details for each study arm are provided below. This procedure is performed in a hospital environment (ie in surgery) under anaesthetic. .

Anatomical Thermal RFN:

This procedure follows the International Spine Intervention Society (SIS) Guidelines.15 Prior to the procedure, a deep paravertebral block with 1% xylocaine is performed. The C-arm Fluoroscope is aligned in the AP decline view, and 15-20°C ipsilateral oblique to the level in question and 100-mm 16G RFK needles with 10-mm sharp active tips are laid parallel to the course of the index medial branches under fluoroscopic vision to perform the radiofrequency neurotomy. Careful view is to be taken to show the uninsulated tip lies opposite the middle two fourths of the neck of the superior articular facet. Three lesions are made at each medial branch by gradually increasing the temperature at about one degree per second until 80-85°C is reached. That temperature is maintained for 90 seconds. Post procedure Naropin 0.75% is injected at the neurotomy sites.

Generic RFN
A C-arm image intensifier is positioned in a slightly (10–15°) oblique position, with the patient in prone position. A 22G SMK needle with a 10-mm active curved tip is introduced at each entry point. The position of the cannula is checked on the lateral and anteroposterior projection. The depth is adjusted until the tip of the cannula is at the level of a line connecting the posterior aspects of the intervertebral foramen. Sensory stimulation (50Hz) is positive when the patient feels paresthesia, and motor stimulation (2Hz) is positive with visible muscle stimulation but no leg contractions. Once the position of the electrode is satisfactory, 1-2 mL per level of 2% lidocaine is injected and a 90°C 90 seconds radiofrequency lesion is made of the medial ramus dorsalis of L3-4, L4-5, and L5-S1.

The procedures will be performed by pain physicians and/or pain specialists and the patients will be 'repeat' patients who have previously benefited from RFN treatment and seek re-treatment. Re-treatment is often required because the nerve usually recovers over time (typically after 12 months or more) from this treatment. As the nerve recovers, sometimes the pain also returns.

The treatment will be a single procedure in each study arm. If the procedure is not successful, the patient will be offered the alternative treatment of the other study arm. The patients will complete questionnaires at various time points over a 12 month period to assess their pain levels at various intervals following the procedure. A summary of the patients' visits is provided below:

Visit 1 - screening/enrolement
Visit 2 - RFN procedure (hospital)
1 month pain assessment (postage/email of pain diary for completion and return)
Visit 3 - 2 month follow up including pain assessment (patient offered alternative treatment if initial outcome unsatisfactory). Options: Group A - successful treatment (obtaining 50% or more pain relief), Group B - unsuccessful pain relief, patient offered and accepted to have alternative procedure, or Group C - unsuccessful pain relief, patient offered but did not accept to have alternative procedure. Note that unsuccessful pain relief is defined as obtaining less than 50% pain relief.
Visit 4A - 6 months post procedure follow up including pain assessment
Visit 5A - 12 months post procedure follow up including pain assessment
Visit 4B - alternative RFN procedure (hospital)
B - 1 month pain assessment postage/email of pain diary for completion and return)
Visit 5B - 2 month follow up including pain assessment
Visit 6B - 6 months post procedure follow up including pain assessment
Visit 7B - 12 months post procedure follow up including pain assessment
Intervention code [1] 301125 0
Treatment: Surgery
Comparator / control treatment
There are no placebo controls, the study compares two active treatment arms to determine whether one is superior to the other.. In addition, patients will act as their own controls measuring their levels of pain before and after treatment.
Control group

Primary outcome [1] 305787 0
The primary outcome measure will be a comparison of pain intensity scores with the NPRS between the two groups
Timepoint [1] 305787 0
2 months after the intervention
Secondary outcome [1] 346538 0
Comparison of pain intensity scores with the NPRS between the two groups
Timepoint [1] 346538 0
1, 6 and 12 months after the intervention.
Secondary outcome [2] 346539 0
Comparison of Depression, Anxiety and Stress Scores (DASS21) between the two groups
Timepoint [2] 346539 0
1, 2, 6 and 12 months after the intervention
Secondary outcome [3] 346540 0
Comparison of Oswestry Disability Index (ODI) scores between the two groups
Timepoint [3] 346540 0
1, 2, 6 and 12 months after the intervention

Key inclusion criteria
To participate in this study, subjects must meet all of the following inclusion criteria:
1. Have been diagnosed with lumbar medial branch derived facet pain via positive medial branch blocks
2. Have received pain relief from a prior RFN procedure.
3. Have agreed to undergo another RFN treatment.
4. Have an average pain intensity of 5 or more out of 10 on the NPRS.
5. Aged 40 to 70 years of age.
6. Be capable of subjective evaluation, able to read and understand ethics committee approved written questionnaires, and are able to read, understand and sign the EC-approved written informed consent, all of which will be in Australian English.
7. Be willing and able to comply with study-related requirements, procedures and visits.
Minimum age
40 Years
Maximum age
70 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
To participate in this study, subjects must not meet any of the following exclusion criteria:
8. Have a body mass index (BMI) >40.
9. Unable to give informed consent.
10. Have a medical condition or pain in other area(s) not intended to be treated with RFN, that could interfere with study procedures, accurate pain reporting, and/or confound evaluation of study endpoints, as determined by the Investigator
11. Have evidence of an active disruptive psychological disorder or other known condition significant enough to impact perception of pain and/or the ability to evaluate treatment outcome as determined by the investigator and the subject’s medical history.
12. Have a co-existing major illness which may interfere with the treatment, as determined by the investigator.
13. Are currently taking > 10 morphine milligram equivalents (MME) per day.
14. Are suffering pain that is different to the previously treated pain from RFN treatment.
15. Are on workcover, TAC or similar.
16. Need treatment for 4 or more spine levels on one side.
17. Have a life expectancy of less than 1 year.
18. Be pregnant or planning to become pregnant during the course of the study (if female and sexually active, subject must be using a reliable form of birth control, be surgically sterile or be at least 2 years post-menopausal).
19. Have within 6 months of enrolment a significant untreated addiction to dependency producing medications or have been a substance abuser (including alcohol and illicit drugs).
20. Be concomitantly participating or planning to participate in another clinical study overlapping in time with the present clinical study.
21. Have a condition currently requiring or likely to require surgery during the study period.
22. Be concomitantly undertaking a physical therapy regimen.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Yes - allocation concealment
To prevent against both selection and accidental bias, patients will be randomly assigned on a one to one basis to one treatment arm – anatomical thermal RFN or generic RFN by the study coordinator who will use an online randomisation tool.

The outcome of the randomization will be communicated to the doctor by the study coordinator prior to the treatment of each patient. Treatment allocation will be concealed from patients until the Visit 3 assessment.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
An online randomization tool, GraphPad Software QuickCalcs, will be used to randomly select patients for each treatment arm. The GraphPad Calculator will draw 49 subjects out of the whole sample who will receive the anatomical thermal RFN treatment, the remaining 49 patients will be assigned to the Generic RFN treatment arm.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s

Intervention assignment
Other design features
Study is Parallel but if patient not satisfied with treatment at Visit 3 Assessment, they have the option to cross over to the other treatment
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
The level of significance was set to 0.05 with a 2-sided test. The standard deviation was estimated to be 3 units of the NPRS. The clinically important difference was judged to be 2 units. With these settings a sample size of 49 per arm, randomised 1:1, would be required to achieve a power of 90%. Therefore, the total sample size needed to complete the primary endpoint assessment visit of 8 weeks post first procedure is 98 subjects.
Dropouts are not expected as the patients are seeking repeated treatment, however, the total sample size may be increased to 110 to allow for dropouts if required.

Recruitment status
Reason for early stopping/withdrawal
Participant recruitment difficulties
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 10856 0
Metro Pain Group - Clayton
Recruitment postcode(s) [1] 22600 0
3168 - Clayton

Funding & Sponsors
Funding source category [1] 299409 0
Other Collaborative groups
Name [1] 299409 0
Monash Clinical Research
Address [1] 299409 0
Monash House, 271 Clayton Road, Clayton, VIC 3168
Country [1] 299409 0
Primary sponsor type
Other Collaborative groups
Monash Clinical Research
Monash House, 271 Clayton Road, Clayton, VIC 3168
Secondary sponsor category [1] 298696 0
Name [1] 298696 0
Address [1] 298696 0
Country [1] 298696 0

Ethics approval
Ethics application status
Ethics committee name [1] 300311 0
Bellberry Limited
Ethics committee address [1] 300311 0
129 Glen Osmond Road Eastwood South Australia 5063
Ethics committee country [1] 300311 0
Date submitted for ethics approval [1] 300311 0
Approval date [1] 300311 0
Ethics approval number [1] 300311 0

Brief summary
This clinical research study is comparing two techniques of radiofrequency neurotomy (RFN) treatment for chronic lower back pain that originates from facet joints. Patients taking part in this research study will therfore have chronic low back pain originating from facet joints. In addition, to take part in this study, the patients will have previously benefited from an RFN procedure and agreed to undergo another RFN procedure.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 83250 0
Dr Dan Bates
Address 83250 0
Metro Pain Group
Monash House, 271 Clayton Road, Clayton, VIC 3168
Country 83250 0
Phone 83250 0
+61 3 9595 6111
Fax 83250 0
+61 3 9595 6110
Email 83250 0
Contact person for public queries
Name 83251 0
Dr Jacqui Young
Address 83251 0
Monash Clinical Research
Monash House, 271 Clayton Road, Clayton, VIC 3168
Country 83251 0
Phone 83251 0
+61 3 9595 6111
Fax 83251 0
+61 3 9595 6110
Email 83251 0
Contact person for scientific queries
Name 83252 0
Dr Jacqui Young
Address 83252 0
Monash Clinical Research
Monash House, 271 Clayton Road, Clayton, VIC 3168
Country 83252 0
Phone 83252 0
+61 3 9595 6111
Fax 83252 0
+61 3 9595 6110
Email 83252 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment
Study has been closed without any recruitment. No data available to share.
What supporting documents are/will be available?
No other documents available
Summary results
No Results