Central Nervous System Amplification in Lumbar Failed Back Surgery Syndrome

An observational study of Chronic Pain, run by University of Kansas Medical Center at 1 site in United States.

Completed

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

Trial summary

The purpose of this study is to learn whether or not certain risk factors and patient characteristics are linked with and possibly can predict the development of chronic pain after lumbar spine surgery. Read more about this study

Who is it for?: Ages 22 to 70 yearsHealthy volunteers can take part
Conditions the study is for: Chronic Pain
How many people: 158 participants
Where: 1 siteUnited States
Study dates: 29 Jun 2018to 20 Apr 2023
Phase: Observational
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 22 to 70 years
All sexes
Healthy volunteers accepted
Adult, Older adult

Study population: Participants will be recruited directly by the Candidate and by referral from specialist physicians at the KUMC Marc A. Asher, MD, Comprehensive Spine and Pain Management Center.

Who may be able to join

Ability to read and speak English to allow for written informed consent, phenotyping, and patient-reported outcomes measures
Deemed to be a candidate for primary lumbar spine surgery including but not limited to: lumbar laminectomy, discectomy, and fusion/instrumentation
Diagnostic clinical and radiographic findings including but not limited to: lumbar degenerative disc disease, lumbar disc protrusion, herniation, or extrusion, lumbar spondylosis, lumbar spinal stenosis, lumbar spondylolisthesis or spondylolysis
Willingness to participate in longitudinal follow-up or 6-months after their surgery.
No major diseases or diagnoses influencing pain or function

Who cannot join

Individuals receiving or applying for compensation or disability and other aspects associated with potential secondary gain
Inability to provide written informed consent
Severe physical impairment
Co-morbid medical conditions that may significantly impair physical functional status
Illicit drug or unreported opioid use
Medical or psychiatric conditions that in the judgment of study personnel would preclude participation in this study

Show all 21Show fewer

Pregnant or nursing
Liver failure
Self-reported liver cirrhosis
Self-reported hepatitis
Severe Cardiovascular disease
History of previous lumbar spine surgery
Indication for lumbar spine surgery is due to spinal cancer-related diagnosis
Need for urgent or emergent lumbar spine surgery
Inclusion Criteria for Candidates with Lumbar Failed Back Surgery Syndrome:
Chronic low back pain (+/- leg pain) for >= to 6 months duration after lumbar spine surgery (with or without instrumented fusion)
Low back pain severity is moderate to severe (Numerical Rating Scale [NRS] Score >=4)
Exclusion Criteria for Candidates with Lumbar Failed Back Surgery Syndrome:
Have a structural spinal lesion that would make them a current candidate for a revision lumbar spine surgery
No chronic pain condition
Score 3 or greater on the 2011 FM Survey Criteria (i.e. individuals with very mild fatigue or sleep problems will be allowed to participate as this is extremely common in the general population)

Trial locations and contacts

1 site in 1 country.

United States1 site

University of Kansas Medical Center
Kansas City, Kansas, 66160

Other trials in United States

About this study

Conditions: Chronic Pain
Keywords: lumbar spine surgery, lumbar failed back surgery syndrome
Medical subject headings: Chronic Pain, Failed Back Surgery Syndrome

What participants receive

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

Study groups in NCT03444168
Study group	Role	What they receive
Candidate for Lumbar Spine Surgery		Participants have been designated to be a candidate for lumbar spine surgery to treat chronic low back and/or leg pain and you have agreed to proceed with the surgery.
Lumbar Failed Back Surgery Syndrome		Participants have been diagnosed with having lumbar failed back surgery syndrome and have persistent and moderate-to-severe low back and/or leg pain for more than 6 months after a lumbar spine surgery.
Healthy Volunteer		Participants are a healthy volunteer wishing to participate in a research study.

What is being measured

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

Clinical Pain Severity - 50% Reduction Responders vs Nonresponders
Measured by the Brief Pain Inventory (BPI). The BPI scores are a numerical rating scale and range from 0 to 10. A score of 0 is equal to no pain and a score of 10 is equal to pain as bad as you can imagine.
Measured: Change from Baseline to Month 6
Fibromylagia-ness (FMness)
2011 Fibromyalgia Survey score is calculated by combining the widespread pain index (WPI) and the Symptom Severity Scale (SSI) to derive a score from 0-31. Scores greater than or equal to 13 indicate a diagnosis of Fibromyalgia. Higher scores indicate the degree of central sensitization present in a given individual.
Measured: Baseline
PROMIS T-score - Fatigue, Physical Function, Sleep-Related Impairment
PROMIS measures to be included are Depression, Anxiety, Physical Functioning, Fatigue, Sleep Impairment, Emotional Support, and Social Participation. Each questionnaire usually has 4-16 response options ranging in value from one to five. The total raw score for a short form with all questions answered is the sum of the values of the response to each question. The total range of potential raw scores depends on the number of questions being asked, for example, a 6 item form would have a range from is 6 to 30. After the raw score is calculated, a T-score metric is used to convert the raw score to a T-score. On the T-score metric, a score of 50 is the mean of a relevant reference population and 10 is the standard deviation of that mean. For PROMIS measures, higher scores equals "more of the concept being measured", this could be a desirable or undesirable outcome, depending on the concept being measured.
Measured: Baseline
PROMIS T-score - Anxiety, Depression, Emotional Support, Pain Interference, Satisfaction With Social Roles
PROMIS measures to be included are Depression, Anxiety, Physical Functioning, Fatigue, Sleep Impairment, Emotional Support, and Social Participation. Each questionnaire usually has 4-16 response options ranging in value from one to five. The total raw score for a short form with all questions answered is the sum of the values of the response to each question. The total range of potential raw scores depends on the number of questions being asked, for example, a 6 item form would have a range from is 6 to 30. After the raw score is calculated, a T-score metric is used to convert the raw score to a T-score. On the T-score metric, a score of 50 is the mean of a relevant reference population and 10 is the standard deviation of that mean. For PROMIS measures, higher scores equals "more of the concept being measured", this could be a desirable or undesirable outcome, depending on the concept being measured.
Measured: Baseline
Oswestry Disability Index
The Oswestry Disability Index will be used to assess low back pain. There are 10 sections on the index. Each section has a possible score of 5. The total possible range of scores is 0 to 50. A score of 0 indicates no pain. A score of 50 indicates the person is bed-bound or exaggerating their symptoms.
Measured: Baseline

Secondary outcomes (1)

Coping Strategies Questionnaire - CAT
A 6-item catastrophizing scale that measures ways to cope or deal with pain. Each item is scored on a scale of 0-6. Scores can range from 0-36, with the higher the score the higher the rate of catastrophizing.
Measured: Baseline

Timeline

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

29 Jun 201820 Apr 2023

First posted23 Feb 2018
Study start29 Jun 2018
Primary completion20 Apr 2023
Study completion20 Apr 2023

Resources

Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
Other trials for Chronic PainStudies of the same condition, open and under way.
What the trial phases meanHow a treatment moves from first tests in people to approval.

More details

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

Study design

Study type: Observational
Observational model: Cohort
Time perspective: Prospective
Enrolment: 158 participants (actual)

IDs, dates and publications

ClinicalTrials.gov ID: NCT03444168
Sponsor's protocol ID: STUDY00140263
Other IDs: 1K23GM123320-01
Status last verified: Feb 2026
First submitted: 8 Feb 2018
Last updated: 13 Mar 2026
Results posted: Yes, on ClinicalTrials.gov
Data monitoring committee: No
FDA-regulated drug: No
FDA-regulated device: No

Want to know more?

The sponsor has not listed a contact. The official record may have more details.

Talk to your doctor first and take this page with you. Only the study team can confirm whether you can join.

Questions to ask the study team

What is the study trying to find out?
What would I need to do, and how often would I visit?
Could I receive a placebo instead of the treatment?
What are the possible risks and benefits for me?
Will it cost me anything? Are travel or time paid for?
Can I keep seeing my own doctor during the study?
What happens when the study ends?

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All Chronic Pain trials

Study at a glance

From the registry record, last updated by the sponsor on 13 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title: Central Nervous System Amplification in Lumbar Failed Back Surgery Syndrome
ClinicalTrials.gov ID: NCT03444168
Acronym / sponsor ID: STUDY00140263
Conditions: Chronic Pain
Keywords: lumbar spine surgery, lumbar failed back surgery syndrome
Study type: Observational
Recruitment status: Completed
Enrolment: 158 participants (actual)
Lead sponsor: University of Kansas Medical CenterUniversity, hospital or other
Collaborators: National Institute of General Medical Sciences (NIGMS)
Study start: 29 Jun 2018 (actual)
Primary completion: 20 Apr 2023 (actual)
Study completion: 20 Apr 2023 (actual)
First posted: 23 Feb 2018 (actual)
Results: Posted 13 Mar 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Observational model: Cohort
Time perspective: Prospective
Number of arms: 3

Arm	Type	Receives
Candidate for Lumbar Spine Surgery	–	–Participants have been designated to be a candidate for lumbar spine surgery to treat chronic low back and/or leg pain and you have agreed to proceed with the surgery.
Lumbar Failed Back Surgery Syndrome	–	–Participants have been diagnosed with having lumbar failed back surgery syndrome and have persistent and moderate-to-severe low back and/or leg pain for more than 6 months after a lumbar spine surgery.
Healthy Volunteer	–	–Participants are a healthy volunteer wishing to participate in a research study.

Who may qualify

Ages: 22 to 70 years
Sex: All
Healthy volunteers: Accepted
Age groups: Adult, Older adult
Study population: Participants will be recruited directly by the Candidate and by referral from specialist physicians at the KUMC Marc A. Asher, MD, Comprehensive Spine and Pain Management Center.

Key inclusion criteria (5 listed)

Ability to read and speak English to allow for written informed consent, phenotyping, and patient-reported outcomes measures
Deemed to be a candidate for primary lumbar spine surgery including but not limited to: lumbar laminectomy, discectomy, and fusion/instrumentation
Diagnostic clinical and radiographic findings including but not limited to: lumbar degenerative disc disease, lumbar disc protrusion, herniation, or extrusion, lumbar spondylosis, lumbar spinal stenosis, lumbar spondylolisthesis or spondylolysis
Willingness to participate in longitudinal follow-up or 6-months after their surgery.
No major diseases or diagnoses influencing pain or function

Key exclusion criteria (21 listed)

Individuals receiving or applying for compensation or disability and other aspects associated with potential secondary gain
Inability to provide written informed consent
Severe physical impairment
Co-morbid medical conditions that may significantly impair physical functional status
Illicit drug or unreported opioid use

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Primary outcome

Clinical Pain Severity - 50% Reduction Responders vs Nonresponders
Time frame: Change from Baseline to Month 6
Measured by the Brief Pain Inventory (BPI). The BPI scores are a numerical rating scale and range from 0 to 10. A score of 0 is equal to no pain and a score of 10 is equal to pain as bad as you can imagine.
Fibromylagia-ness (FMness)
Time frame: Baseline
2011 Fibromyalgia Survey score is calculated by combining the widespread pain index (WPI) and the Symptom Severity Scale (SSI) to derive a score from 0-31. Scores greater than or equal to 13 indicate a diagnosis of Fibromyalgia. Higher scores indicate the degree of central sensitization present in a given individual.
PROMIS T-score - Fatigue, Physical Function, Sleep-Related Impairment
Time frame: Baseline
PROMIS measures to be included are Depression, Anxiety, Physical Functioning, Fatigue, Sleep Impairment, Emotional Support, and Social Participation. Each questionnaire usually has 4-16 response options ranging in value from one to five. The total raw score for a short form with all questions answered is the sum of the values of the response to each question. The total range of potential raw scores depends on the number of questions being asked, for example, a 6 item form would have a range from is 6 to 30. After the raw score is calculated, a T-score metric is used to convert the raw score to a T-score. On the T-score metric, a score of 50 is the mean of a relevant reference population and 10 is the standard deviation of that mean. For PROMIS measures, higher scores equals "more of the concept being measured", this could be a desirable or undesirable outcome, depending on the concept being measured.
PROMIS T-score - Anxiety, Depression, Emotional Support, Pain Interference, Satisfaction With Social Roles
Time frame: Baseline
PROMIS measures to be included are Depression, Anxiety, Physical Functioning, Fatigue, Sleep Impairment, Emotional Support, and Social Participation. Each questionnaire usually has 4-16 response options ranging in value from one to five. The total raw score for a short form with all questions answered is the sum of the values of the response to each question. The total range of potential raw scores depends on the number of questions being asked, for example, a 6 item form would have a range from is 6 to 30. After the raw score is calculated, a T-score metric is used to convert the raw score to a T-score. On the T-score metric, a score of 50 is the mean of a relevant reference population and 10 is the standard deviation of that mean. For PROMIS measures, higher scores equals "more of the concept being measured", this could be a desirable or undesirable outcome, depending on the concept being measured.
Oswestry Disability Index
Time frame: Baseline
The Oswestry Disability Index will be used to assess low back pain. There are 10 sections on the index. Each section has a possible score of 5. The total possible range of scores is 0 to 50. A score of 0 indicates no pain. A score of 50 indicates the person is bed-bound or exaggerating their symptoms.

1 secondary outcome

Coping Strategies Questionnaire - CAT
Time frame: Baseline

Results and safety

Results posted to the registry on 13 Mar 2026, as reported by the sponsor. Figures are copied from the record, not re-analysed. Full results on ClinicalTrials.gov.

Participant flow

Group	Started	Completed
Candidate for Lumbar Spine Surgery	64	55
Lumbar Failed Back Surgery Syndrome	54	49
Healthy Volunteer	40	40

Primary outcome: Clinical Pain Severity - 50% Reduction Responders vs Nonresponders

Time frame: Change from Baseline to Month 6. Median (Inter-Quartile Range). Unit: percentage of change

Measure	Lumbar Spine Surgery - Responders n = 21	Lumbar Spine Surgery - Non-Responders n = 31
Value	-83 (-100 to -62.5)	0 (-12.5 to 15.5)

Population analysed: Lumbar Spine Surgery Candidates (LSS) were asked BPI prior to surgery (baseline) and 6 months post surgery. Based on this response, participants were split in to two groups, responders vs non-responders. Responders were defined as patients who reported a \>50% reduction in pain on the BPI. Only participants in the LSS group participated in longitudinal follow-up.

Primary outcome: Fibromylagia-ness (FMness)

Time frame: Baseline. Count of participants. Unit: Participants

Measure	Lumbar Spine Surgery - Responders n = 21	Lumbar Spine Surgery - Non-Responders n = 31	Lumbar Failed Back Surgery Syndrome n = 49	Healthy Volunteer n = 40
FM Negative	17	27	26	40
FM positive	4	4	23	0

Population analysed: Lumbar Spine Surgery Candidates were asked BPI prior to surgery (baseline) and 6 months post surgery. Based on this response, participants were split in to two groups, responders vs non-responders. Responders were defined as patients who reported a \>50% reduction in pain on the BPI. health surgery syndrome.

Primary outcome: PROMIS T-score - Fatigue, Physical Function, Sleep-Related Impairment

Time frame: Baseline. Median (Inter-Quartile Range). Unit: units on a scale

Measure	Lumbar Spine Surgery - Responders n = 21	Lumbar Spine Surgery - Non-Responders n = 31	Lumbar Failed Back Surgery Syndrome n = 49	Healthy Volunteer n = 40
Fatigue v1.0 8a	58.80 (51.40 to 64.40)	56.40 (48.10 to 61.50)	62.40 (57.10 to 66.10)	42 (33.10 to 47.70)
Physical Function v2.0 8b	34.70 (31.80 to 36.30)	35.30 (30.40 to 40.60)	34.30 (32.00 to 36.30)	60.10 (52.80 to 60.10)
Sleep-Related Impairment v1.0 8a	60.90 (52.50 to 66.00)	59.70 (50.50 to 62.90)	62.30 (53.10 to 66.10)	44.60 (38.40 to 50.30)

Primary outcome: PROMIS T-score - Anxiety, Depression, Emotional Support, Pain Interference, Satisfaction With Social Roles

Time frame: Baseline. Median (Inter-Quartile Range). Unit: units on a scale

Measure	Lumbar Spine Surgery - Responders n = 21	Lumbar Spine Surgery - Non-Responders n = 31	Lumbar Failed Back Surgery Syndrome n = 49	Healthy Volunteer n = 40
Anxiety v1.0 8a	50.3 (44 to 61)	49.8 (43.9 to 54.6)	51.00 (45.90 to 60.10)	43.35 (37.10 to 50.60)
Depression v1.0 8a	54.5 (49.6 to 56.8)	52.0 (38.2 to 56.9)	54.00 (45.50 to 58.60)	41.35 (38.20 to 49.60)
Emotional Support v2.0 4a	52.1 (48.9 to 62)	62.0 (48.9 to 62.0)	56.20 (48.90 to 62.00)	62.00 (48.90 to 62.00)
Pain Interference v2.0 8b	66.9 (64.7 to 72.2)	61.6 (58.4 to 70.1)	66.20 (61.60 to 67.60)	40.70 (40.70 to 40.70)
Satisfaction with Social Roles v1.0 4a	37.5 (30.1 to 44.8)	41.8 (30.1 to 51.8)	37.40 (34.90 to 43.00)	57.50 (51.80 to 63.70)

Population analysed: 141 participants were analyzed at baseline. 3 participants did not have complete baseline data for these instruments and thus were not included in analysis. Lumbar Spine Surgery Pts were asked BPI prior to surgery (baseline) and 6 months post surgery. Based on this response, participants were split in to two groups. Responders were defined as patients who reported a \>50% reduction in pain on the BPI. Results were compared to the healthy controls and failed back surgery syndrome participants.

1 secondary outcome is reported in the full results.

Adverse events

Time frame: AEs were assessed via pt-report or via EMR notification for the duration of the study, approximately 6 months.. Other adverse events reported at 0% frequency or more

Group	Serious adverse events	Other adverse events	Deaths
Lumbar Spine Surgery Candidates	1 of 55 (1.8%)	0 of 55 (0%)	1 of 55
Healthy Control Participants	0 of 40 (0%)	0 of 40 (0%)	0 of 40
Failed Back Surgery Syndrome Participants	0 of 49 (0%)	0 of 49 (0%)	0 of 49

Limitations and caveats (from the sponsor): Trial was conducted during the start of COVID-19, which drastically impacted surgery number and selection.

Loading the posted results from ClinicalTrials.gov…

Research links

Official record on ClinicalTrials.govLast updated by the sponsor 13 Mar 2026.
Posted resultsParticipant flow, baseline, all outcome measures and adverse events.

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Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

Andrea Chadwick, MD principal investigator

University of Kansas Medical Center

1 site in 1 country: see every site and its status.

Questions about this trial

What is this clinical trial studying?

An observational study of Chronic Pain, run by University of Kansas Medical Center at 1 site in United States.

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 5 inclusion and 21 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 13 Mar 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 United States. 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. 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 13 Mar 2026). 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?

Clinical Pain Severity - 50% Reduction Responders vs Nonresponders (time frame: Change from Baseline to Month 6). The study lists 5 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 NCT03444168.

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 13 Mar 2026.