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Trial registered on ANZCTR

Registration number

ACTRN12608000365369

Ethics application status

Approved

Date submitted

15/07/2008

Date registered

25/07/2008

Date last updated

25/11/2008

Type of registration

Prospectively registered

Titles & IDs

Public title

A randomised double blind placebo controlled trial of radiofrequency neurotomy for the treatment of lumbar zygapophysial joint pain

Scientific title

A randomised double blind placebo controlled trial of radiofrequency neurotomy for the treatment of lumbar zygapophysial joint pain

Secondary ID [1]

Nil

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Lumbar zygapophysial joint pain

Condition category

Condition code

Musculoskeletal

Other muscular and skeletal disorders

Neurological

Other neurological disorders

Physical Medicine / Rehabilitation

Other physical medicine / rehabilitation

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

Radiofrequency Neurotomy (RFN) involves the insertion of an insulated needle electrode (probe) with an exposed tip into contact or close proximity to a target nerve under local anaesthetic and radiological control. A RF generator applies current to raise the temperature of the exposed tip of the probe to 80-85 degrees celcius and maintained at that level for 90 seconds, in order to coagulate the target nerve and disrupt the conduction of nociceptive (pain producing) impulses along that nerve. This outcome is acheived in one single treatment.

Intervention code [1]

Treatment: Devices

Comparator / control treatment

This is a placebo controlled trial. Placebo patients will have the electrode placed on to the nerve of interest, however no heat will be applied through the electrode, resulting in the nerve being unaffected.

Control group

Placebo

Outcomes

Primary outcome [1]

The objective is to determine the efficacy of lumbar medial branch neurotomy, for proven lumbar zygapophysial joint pain. The primary outcome measure will be relief of pain. This will be done by self-assessment using a numerical pain rating scale and by doctor assessments at the follow up visits.

Timepoint [1]

A pre-treatment assessment will be made, whilst follow up assessments will be scheduled at 3, 6, 9 and 12 months following treatment.

Secondary outcome [1]

Comparison between pre treatment and post treatment disability and depression scores. These outcome measures will be measured by patient and doctor answered questionnaires. These questionnaires will consist of the Quality of Life (AQoL), SF-36, Roland-Morris diability scale and the patient-specified functional outcome measure questionnaire.

Timepoint [1]

A pre-treatment assessment will be made, whilst follow up assessments will be scheduled at 3, 6, 9 and 12 months following treatment.

Eligibility

Key inclusion criteria

1. Low back pain for a duration of more than 3 months
2. Pain severity of at least 5/10 on a visual analogue scale, which is sufficient to warrant invasive treatment
3. Complete, or vitually complete, relief of pain in response to controlled, medial branch blocks performed on at least two occasions.
4. Up to, but not exceeding two sympathetic zygapophysial joints per side

Minimum age

18 Years

Maximum age

No limit

Sex

Both males and females

Can healthy volunteers participate?

Key exclusion criteria

1. Unable to provide informed consent
2. Unable to complete the assessment instruments
3. Anatomical abnormalities that might interfere with the safe conduct of the treatment
4. Any illness or disorder that might interfere with the safe conduct of treatment
5. Overt, clinically evident psychological disturbance, such as severe depression, drug dependence, or drug-seeking behaviour that might interfere with the assessment or response to treatment
6. Concomitant cervical, thoracic, hip, or other pain, of an intensity greater than 2/10 (on the visual analogue scale (VAS))or otherwise, which may interfere with the assessment or response to treatment

Study design

Purpose of the study

Treatment

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

All patients will be recruited from amongst the patients seen in the normal course of the clinical practice, by the participating pain specialist. Patients with pain stemming from one or more lumbar zygapophysial joints as diagnosed by diagnostic blocks, conducted in the course of normal patient care, will be invited to participate. Allocation concealment will be carried out by computerised central randomisation carried out offsite. Randomised results will be placed in sealed opaque envelopes.

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Simple randomisation using a computerised sequence generator

Masking / blinding

Blinded (masking used)

Who is / are masked / blinded?

Intervention assignment

Parallel

Other design features

Phase

Not Applicable

Type of endpoint/s

Efficacy

Statistical methods / analysis

Recruitment

Recruitment status

Recruiting

Date of first participant enrolment

Anticipated

1/11/2008

Actual

Date of last participant enrolment

Anticipated

Actual

Date of last data collection

Anticipated

Actual

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

Funding & Sponsors

Funding source category [1]

Charities/Societies/Foundations

Name [1]

International Spinal Intervention Society

Address [1]

5 Ash Avenue, Kentfield California, USA 94904

Country [1]

United States of America

Primary sponsor type

Individual

Name

Dr. Paul Verrills

Address

Level 1 544 Hawthorn Road,
Caulfield South Victoria 3162

Country

Australia

Secondary sponsor category [1]

Individual

Name [1]

Adele Barnard

Address [1]

Level 1 544 Hawthorn Road,
Caulfield South Victoria 3162

Country [1]

Australia

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

The Avenue Ethics Committee

Ethics committee address [1]

Ethics committee country [1]

Date submitted for ethics approval [1]

19/08/2008

Approval date [1]

19/09/2008

Ethics approval number [1]

Summary

Brief summary

In most patients with chronic low back pain, the cause of their pain is unknown. As well, there are very few proven treatments for chronic low back pain, and none of the commonly used treatments are known to relieve pain completely.

However, in a small proportion of patients, the source of pain can be traced to one or more small joints in the lumbar spine, called the zygapophysial joints – or “Z” joints for short. Pain from these joints can be relieved by sealing the small nerves that supply the joints. This is done using a probe inserted, under X-ray control, onto each of the nerves. The probe delivers a tiny heat-lesion that seals the nerve.

In full, this procedure is called percutaneous lumbar medial branch radiofrequency neurotomy. In short, it is known as radiofrequency, or RF neurotomy.

Lumbar RF neurotomy is not an experimental procedure. It has been used in Medicine for nearly 30 years. In Australia, it is recognized in having a Medicare item number.

Doctors who use this procedure to treat their patients believe that it works. However, some commentators have questioned if the results of the operation are genuine. They believe that patients report relief because of non-specific effects of the procedure – such as the ceremony of having an operation, or because patients want it to work. They argue that it is not necessary actually to coagulate the nerves in order to achieve a beneficial effect. 

This argument arises because there has been no rigorous scientific studies of the procedure in the form of controlled trials. In a controlled trial, a computer indicates whether patients should undergo the real treatment or a sham treatment. A sham treatment is one which is just like the real treatment but differs in one critical respect. In the present study, the difference is that in the sham procedure not actually coagulated.

If an operation works in such a study, the results obtained from the real treatment emerge as better than those obtained from the sham treatment. The difference in results indicates how powerful the real treatment is. However, if there is no difference in the results, any apparent effectiveness of the treatment is attributed to non-specific influences.

Some controlled trials for lumbar RF neurotomy have been conducted, but in each instance the operators used techniques that have been shown to fail to coagulate the target nerves accurately. In the one study in which correct techniques were used, the investigators found that some 80% of patients obtained at least 60% relief of their pain, and 60% of patients obtained at least 80% relief, lasting for at least 12 months after treatment. But these results have been disregarded because the study was not controlled: it provided the real treatment but had no patients who underwent sham treatment.

Because of the lack of convincing scientific evidence that lumbar RF neurotomy actually works, some insurance carriers have undertaken to deny this form of treatment to their clients. This has occurred both in the United States and in Australia.

In response to the conflict between those doctors who believe that lumbar RF neurotomy works and those who believe it does not, the International Spine Intervention Society has provided funding for study of the procedure, to be conducted in which will look at recruiting 30 patient volunteers.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Address

Country

Phone

Fax

Contact person for public queries

Name

Dr. Paul Verrills

Address

Level 1 544 Hawthorn Road,
Caulfield South Victoria 3162

Country

Australia

Phone

+61 3 9595 6111

Fax

[email protected]

Contact person for scientific queries

Name

Adele Barnard

Address

Level 1 544 Hawthorn Road,
Caulfield South Victoria 3162

Country

Australia

Phone

+61 3 9595 6111

Fax

[email protected]

No information has been provided regarding IPD availability

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

No additional documents have been identified.

Trial Review

Documents added manually

Documents added automatically