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Trial registered on ANZCTR

Trial ID
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
The role of sensory parameters in predicting clinical outcome after lumbar discectomy
Scientific title
The role of quantitative sensory testing parameters in predicting clinical outcome in patients undergoing lumbar discectomy
Secondary ID [1] 285063 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Lumbar radiculopathy with radicular pain 292587 0
Condition category
Condition code
Neurological 292891 292891 0 0
Other neurological disorders
Surgery 292892 292892 0 0
Other surgery

Study type
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
The initial participant assessment will be performed in the week prior to surgery. The once-off baseline assessment will take approximately 2.5 hours.
Standardised quantitative sensory testing (QST) will be performed according to the QST protocol of German Research Network on Neuropathic pain. The protocol includes the following assessments: cold and warm detection thresholds; the number of paradoxical heat sensations during the procedure of alternating warm and cold stimuli; cold and heat pain thresholds; mechanical detection threshold; mechanical pain threshold; stimulus-response functions: mechanical pain sensitivity and dynamic mechanical allodynia; wind-up ratio; vibration detection threshold and pressure pain threshold.

QST measurements will be taken from the main pain area nominated by the patient, as required for the assessment of neuropathic pain, and the contralateral side and from the ipsilateral hand dorsum as a remote control site, plus thermal and mechanical detection thresholds will be assessed in the relevant dermatomes (L5 or S1). Testing of the full QST protocol will take approximately 30 minutes per test area. Testing of the dermatomal detection thresholds will take less than 10 minutes.

In addition the following measurements will be taken either in interview format or via questionnaires at the initial assessment before surgery:
*Duration of pain
*Pain intensity of back and leg pain
*Health care utilisation
*Bothersomeness of back and leg pain
*Confidence in recovery (‘great deal’, ‘moderate’, ‘no confidence’, ‘do not know’)
*Intake of medication
*Sleep quality (Visual Analogue Scale)
*Duration of inability to work
*Functional status (Oswestry Disability Index)
*Anxiety and Depression (Hospital Anxiety and Depression Scale)
*Pain descriptors (painDETECT)
*Fear avoidance behaviour (Tampa Scale for Kinesiophobia)
*Pain catastrophizing (Pain catastrophizing Scale)
*Health-related quality of life (Short form-36 health questionnaire)
*Risk assessment for persistent pain (Orebro Musculoskeletal Screening Questionnaire)

Participants will be observed up to 12 months after surgery. The 3 months post-surgery assessment will include the full QST protocol just in the participants' previous maximal pain area and the reassessment of detection thresholds in the relevant dermatome. The QST assessment will take approx. 40 minutes. In addition participants will have to complete questionnaires.
Intervention code [1] 289900 0
Not applicable
Comparator / control treatment
comparison of QST data to QST data of healthy control group; comparison of QST measurements in maximal pain area before and 3 months after lumbar discectomy. The healthy control group will be assessed on a single occasion for the relevant body regions to be tested. In addition to QST measurement they will complete the SF-36 questionnaire, the Hospital Anxiety and Depression Scale
and determine their sleep quality (VAS).
Control group

Primary outcome [1] 292768 0
Oswestry Disability Index
Timepoint [1] 292768 0
3 months and 12 months post surgery
Primary outcome [2] 293250 0
Pain intensity (NRS -11)
Timepoint [2] 293250 0
3 and 12 months post surgery
Secondary outcome [1] 309627 0
Health related quality of life (SF-36)
Timepoint [1] 309627 0
3 and 12 months post surgery
Secondary outcome [2] 310597 0
QST maximal pain area and dermatome
Timepoint [2] 310597 0
3 months post surgery
Secondary outcome [3] 310672 0
pain descriptors (painDETECT)
Timepoint [3] 310672 0
3 and 12 months post surgery
Secondary outcome [4] 310673 0
Return to work (yes/no) (any work:full time, part time or casual)
Timepoint [4] 310673 0
3 and 12 months post surgery
Secondary outcome [5] 310674 0
Patient Global Impression of Change Scale
Timepoint [5] 310674 0
3 and 12 months post surgery
Secondary outcome [6] 310675 0
Bothersomenes of back and leg pain ;
Q: how bothersome has your back/leg pain been in the last 2 weeks? Answer: not at all, slightly, moderately, very much, extremely
Timepoint [6] 310675 0
3 and 12 months post surgery
Secondary outcome [7] 310676 0
Health care utilisation ; outcome assessed by questionnaire:
Q: What treatment options have you accessed in the past 4 weeks for your pain condition? Several health professionals are given as answer, plus participant has to indicate the number of times visited. There is no data linkage to medical records,.
Timepoint [7] 310676 0
3 and 12 months post surgery
Secondary outcome [8] 310677 0
Medication intake ; assessed by questionnaire - participant has to write down name of current medication, dosage and reason for taking this medication
Timepoint [8] 310677 0
3 and 12 months post surgery

Key inclusion criteria
Age 18 to 65 years; symptom duration of > 3 months; clinical diagnosis of lumbar radiculopathy (defined as conduction block along a spinal nerve or nerve root, manifesting clinically with dermatomal sensory loss or myotomal weakness or reflex changes) and leg pain in L5 or S1 dermatomal distribution; demonstrable clinically relevant abnormality on imaging studies indicating nerve root compression at the relevant spinal level; person listed on the elective neurosurgery surgery waitlist for the procedure of lumbar discectomy.
Minimum age
18 Years
Maximum age
65 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
diabetes and vascular disease, thyroid disorder, other neurological or psychiatric disease; previous lumbar surgery; a history of any disorders that potentially might affect the sensation in the hand (negative control site) to be tested and an insufficient level of English to understand and fill out the questionnaires

Study design
Natural history
Case control
Statistical methods / analysis
Sample Size: In 2013 approximately 70 lumbar discectomies were performed on patients on the elective neurosurgery list by the consultant neurosurgeon involved in this study. A sample of 70 participants is feasible for this study, considering the exclusion criteria, loss to follow up and the given time frame of the PI’s fellowship.

The Oswestry Disability Index (ODI) will be used as primary outcome measure after surgery. The scoring of ODI is between 0-100 (100 maximum disability).
10 points or 30% score improvement is the cut-off point for minimal important change. A sample size of 40 participants is required to detect 10 units pre-post surgery with a power of 80% and 5% level of significance.

The number of healthy control (HC) subjects to be tested has to be determined during the course of the study, as reference data have to be obtained from at least 8 male and 8 female HC subjects for each maximal pain area nominated by the symptomatic participants and for the dermatomes.

QST data will be log-transformed prior to statistical analysis except those data which are normally distributed as raw data . To compare and illustrate particpants’ QST data profiles with the group mean of age/gender matched healthy controls particpants’ data will be z-transformed for each single parameter by using the following expression: Z-score = (Mean single proband – Mean healthy controls)/SD healthy controls . Z-values will be calculated based on the HC group data.

Differences of z-score QST data between the symptomatic participant group and HC and tested body regions will be compared using a two-way analysis of covariance (ANCOVA) with tested body areas (maximal pain area, hand) as the within-subjects factor. Group (participants/controls) will be entered as between-subjects factors. Anxiety, depression and fear avoidance scores will be entered as covariates to account for potential influence of these factors on pain responses. Depending on data distribution, differences of some predictor variables (Oswestry Disability Index, HADS,Tampa Scale for Kinesiophobia , SF-36v2 'Registered Trademark' ) between patients and HC will be compared using parametric (t-Test) or non-parametric tests (Mann-Whitney-U test).

Differences in outcome measures pre- and post-surgery will be compared using repeated measures ANOVA in case of normal distribution of variables, and the Friedman’s Test for non-normal distributed data. Multivariate regression analyses will be performed to assess associations between the predictor variables, QST measures and the outcome variables.

Recruitment status
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] 2785 0
Sir Charles Gairdner Hospital - Nedlands
Recruitment postcode(s) [1] 8478 0
6009 - Broadway Nedlands

Funding & Sponsors
Funding source category [1] 289668 0
Name [1] 289668 0
Raine Medical Research Foundation
Address [1] 289668 0
Raine Medical Research Foundation,
The University of Western Australia, Mail Bag 651
Suite 24, Hollywood Specialist Centre
95 Monash Avenue, Nedlands, WA 6009
Country [1] 289668 0
Funding source category [2] 290028 0
Government body
Name [2] 290028 0
Government of Western Australia, Department of Health
Address [2] 290028 0
Raine Medical Research Foundation,
The University of Western Australia, Mail Bag 651
Suite 24, Hollywood Specialist Centre
95 Monash Avenue, Nedlands, WA 6009
Country [2] 290028 0
Primary sponsor type
Dr Brigitte Tampin
Neurosurgery Spinal Clinic, Dept of Pain Management
G Block, Lower Ground Floor
Sir Charles Gairdner Hospital
Hospital Avenue
Nedlands WA 6009
Secondary sponsor category [1] 288359 0
Name [1] 288359 0
Address [1] 288359 0
Country [1] 288359 0
Other collaborator category [1] 278065 0
Name [1] 278065 0
School of Physiotherapy and Exercise Science
Curtin University
Address [1] 278065 0
GPO Box 1987
Perth WA 6845
Country [1] 278065 0

Ethics approval
Ethics application status
Ethics committee name [1] 291405 0
Sir Charles Gairdner Group Human Research Ethics Committee
Ethics committee address [1] 291405 0
Sir Charles Gairdner Hospital
Level 2 A Block,
Hospital Avenue
Nedlands WA 6009
Ethics committee country [1] 291405 0
Date submitted for ethics approval [1] 291405 0
Approval date [1] 291405 0
Ethics approval number [1] 291405 0

Brief summary
Low back pain is one of the most common health problems and affects 80 – 85% of people over their life time. Health costs due to back problems in Australia were estimated to be $4.79 million in 2012. Low back-related leg pain or sciatica is a common variation of low back pain and may require back surgery. Thirty percent of people report persistent pain after back surgery which is associated with disability, reduced quality of life, reduced work capacity and substantial health care costs. Whilst several risk factors have been identified (e.g. psychological factors such as catastrophising, unhelpful beliefs about pain and disability) for poor outcome after surgery, the role of pre-sensory pain sensitivity is unknown. Research suggests that certain people who demonstrate hypersensitivity to sensory stimuli such as hot/cold, touch and pressure, pin-prick and vibration may be more vulnerable to develop ongoing pain, however this has not yet been explored in people with back and leg pain. This study will investigate if pre-surgical responses to these stimuli may play a role in predicting persistent pain after back surgery. The findings may assist in developing pre-surgical screening methods and in using this outcome to target pre- and/or post-operative patient care, with the potential to improve patients’ functional status, quality of life, work capacity whilst also reducing health care costs associated with persistent disability.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 50246 0
Dr Brigitte Tampin
Address 50246 0
Sir Charles Gairdner Hospital
Neurosurgery Spinal Clinic
Department of Pain Management
G Block, Lower Ground Floor
Hospital Avenue
Nedlands WA 6009
Country 50246 0
Phone 50246 0
+61 8 9346 7964
Fax 50246 0
+61 8 9346 3481
Email 50246 0
Contact person for public queries
Name 50247 0
Dr Brigitte Tampin
Address 50247 0
Sir Charles Gairdner Hospital
Neurosurgery Spinal Clinic
Department of Pain Management
G Block, Lower Ground Floor
Hospital Avenue
Nedlands WA 6009
Country 50247 0
Phone 50247 0
+61 8 9346 7964
Fax 50247 0
+61 8 9346 3481
Email 50247 0
Contact person for scientific queries
Name 50248 0
Dr Brigitte Tampin
Address 50248 0
Sir Charles Gairdner Hospital
Neurosurgery Spinal Clinic
Department of Pain Management
G Block, Lower Ground Floor
Hospital Avenue
Nedlands WA 6009
Country 50248 0
Phone 50248 0
+61 8 9346 7964
Fax 50248 0
+61 8 9346 3481
Email 50248 0