Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status
Results overdue

Plain English Summary

Background and study aims
Lumbar back pain is extremely common, but usually gets better over time. Nevertheless, some people become seriously debilitated. It is important to find the specific pain generator responsible for these symptoms. A provocative discogram is a diagnostic test to help identify which of the disc(s) of the spine, if any, are causing pain. The aim of this study is to compare the surgical outcomes of patients operated on with or without discography before the operation.

Who can participate?
Patients aged 23 - 74 with chronic (long-term) low back pain

What does the study involve?
Participants are randomly allocated into two groups. Participants in one group undergo provocative discography to find out the main generator of the pain, and those with positive findings are sent to undergo surgical treatment. Participants in the other group do not undergo provocative discography and all undergo surgery. The surgical outcomes of the two groups are compared.

What are the possible benefits and risks of participating?
All participants undergo standard tests and after that surgical treatment which will hopefully improve their health and physical function. Discography has proven to be a relatively safe procedure. Major risks of procedure include infection, hematoma (a solid swelling of clotted blood) and nerve injury. These complications are extremely rare. The most feared complication is discitis (inflammation between the discs) which is also extremely rare.

Where is the study run from?
University of Zagreb School of Medicine and the Clinic of Traumatology Zagreb (Croatia)

When is the study starting and how long is it expected to run for?
January 2003 to December 2009

Who is funding the study?
Ministry of Health (Croatia)

Who is the main contact?
Petra Margetic

Trial website

Contact information



Primary contact

Prof Marin Stancic


Contact details

Clinic for Neurosurgery
KBC Zagreb
Kispaticeva 12

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

The role of provocative discography in surgical treatment for patients with chronic low back pain: a randomised controlled study


Study hypothesis

Provocative discography is able to locate the precise disc of clinical significance and determine the exact cause of the pain

Ethics approval

1. Medical Ethics Committee of Clinic for Traumatology Zagreb, 28/11/2007
2. Medical Ethics Committee of Zagreb Medical University, 04/02/2008

Study design

Randomised controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details to request a patient information sheet


Low back pain/ischiatic pain


At first all 310 patients were randomized into a trial group with 207 patients and a control group with 103 patients.

Patients in trial group filled in the Oswestry, Zung and MSPQ test, if the results did not show high depression values (Zung results more than 33) and somatisation (MSPQ results more than 12 in patients with Zung results between 18 and 33) we considered the patients adequate to be sent to provocative discography.

Patients with positive findings on provocative discography were sent to surgical treatment. Surgery was performed on patients in trial group with positive finding on discography and also on all patients in control group without discography.

All patients, in both groups were categorized by Thalgott. In cases categorized as C and/or D changes on more segments (mostly two) we performed transpedicular fixation. In cases categorized E and F group by Thalgott we performed circumferential – posterolateral and intercorporal fixation.

Intervention type



Not Applicable

Drug names

Primary outcome measure

1. Statistically significant difference between two pre-operative groups should be 4 points or 8%
2. Statistically significant difference between pre-operative and post-operative groups should be 10 points or 20%

Secondary outcome measures

1. 36-item Short Form Health Survey (SF-36) update
2. Likert bipolar scaling method measuring either positive or negative response to a statement

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Aged 23 - 74 years, either sex
2. Chronic low back pain and ischiatic pain
3. Radiological findings describe more than one cause of the pain
4. Uncertain clinical status after complete diagnostic imaging

Participant type


Age group




Target number of participants

310 patients

Participant exclusion criteria

1. Tumour
2. Trauma
3. Psychiatric disease
4. Pregnancy

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

KBC Zagreb

Sponsor information


KBC Zagreb [Klinički bolnički centar Zagreb] (Croatia)

Sponsor details

c/o Marin Stancic
Clinic for Neurosurgery
Kispaticeva 12

Sponsor type

Hospital/treatment centre



Funder type

Hospital/treatment centre

Funder name

KBC Zagreb [Klinički bolnički centar Zagreb] (Croatia)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

14/02/2017: Plain English summary added.