Spinal FusionNCT06368245
Durability of Suppl. Rod Constructs-SuppleMentAry Rod Technique for Long-segment Posterior Instrumented Spinal Fusions
An observational study of Spinal Fusion, run by AO Foundation, AO Spine at 17 sites in 7 countries.
Trial summary
This is a multicenter retrospective comparative cohort study. The index surgery for this study is primary or revision long-segment posterior thoracolumbar (TL) instrumented fusion using either a supplementary rod construct or a dual-rod construct. Read more about this study
- Who is it for?
- Ages 45 years and older
- Conditions the study is for
- Spinal Fusion
- What is being tested?
- long-segment posterior TL instrumented fusion
- Type of treatment
- Surgery or procedure
- How many people
- 1,244 participants
- Where
- 17 sitesin 7 countries
- Study dates
- 24 Mar 2025to 31 Jul 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 45 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Patients who underwent long-segment posterior thoracolumbar (TL) instrumented fusion
Who may be able to join
- Age 45 years and older.
- Patients receiving long-segment posterior TL instrumented fusion using either supplementary rod constructs or dual-rod constructs (the index surgery).
- Long-segment is defined as the UIV at a thoracic level and the LIV at the sacrum/ilium.
- Supplementary rod constructs are defined as: in addition to the traditional two primary rods, at least one supplementary rod (eg, accessory rods or satellite rods) is used, and at least one supplementary rod and one primary rod (ie, at least two rods) together must span multiple (≥ 2) vertebral levels. The supplementary rod constructs do not include rods connected end-to-end or side-to-side that do not bridge multiple vertebral levels.
- The index surgery can be a primary surgery or a revision surgery.
- The index surgery, staged or non-staged, must use posterior spinal fusion but can be in combination with other approaches such as an anterior procedure.
Show all 11Show fewer
- If the index surgery is a revision surgery, the primary rods must be replaced in the revision surgery, with the exception of Harrington or Luque rods which can remain in place.
- o If the Harrington or Luque rods remain in situ, they must already have the UIV at the thoracic level and the LIV at the sacrum/ilium, or an extension of the existing Harrington or Luque is performed such that the UIV is at the thoracic level and the LIV at the sacrum/ilium.
- The index surgery was performed between January 1, 2014, and December 31, 2020, inclusive.
- Minimum 3 months of FU after the index surgery.
- Ability to provide informed consent according to the IRB/EC defined and approved procedures if applicable for retrospective data analysis.
Who cannot join
- Spinal fusion performed for acute trauma (ie, ≤ 1 year of trauma).
- Spinal fusion performed for tumor.
- Spinal fusion performed for infection.
- Patients with Parkinson's Disease.
- Patients with neuromuscular disorders.
- Patients with spine malignancies requiring chemo- or radiation therapy.
Trial locations and contacts
17 sites in 7 countries. Contact the study team or a site near you to ask about taking part.
17 sites in 7 countries
United States9 sites, 7 recruiting
- Recruiting
John Hopkis Hospital
Baltimore, Maryland, 21287
Khaled Kebaish
- Recruiting
University of Virginia
Charlottesville, Virginia, 22908
Justin S Smith, MD, PhD, 434-243-6339, jss7f@virginia.edu
Judith G Beenhakker, JGB3P@uvahealth.org
- Recruiting
University of Minnesota Medical Center
Minneapolis, Minnesota, 55454
David Polly, MD, pollydw@umn.edu
- Recruiting
Columbia University / NYP Och Spine Hospital
New York, New York, 10032
Zeeshan Sardar
- Recruiting
Stanford Spine Clinic
Redwood City, California, 94588
Serena Hu, MD, shu3@stanford.edu
- Recruiting
University of California
Sacramento, California, 95819
Yashar Javidan, yjavidan@ucdavis.edu
- Terminated
UCSF Spine Center
San Francisco, California, 94144
- Recruiting
Washington University in St. Louis, School of Medicine
St Louis, Missouri, 63110
Brian Neuman
- Completed
Washington University in St. Louis, School of Medicine, Saint Louis, Missouri 63110
St Louis, Missouri, 63310
Canada2 sites, 2 recruiting
- Recruiting
University of Calgary Spine
Calgary, T2N 2T9
Ganesh Swamy
- Recruiting
University of Toronto
Toronto, M5T 2S8
Stephen Lewis
Christopher Nielsen
Japan2 sites, 1 recruiting
- Completed
Hamamatsu University School of Medicine
Hamamatsu, 431-3192
- Recruiting
University of Tokyo
Tokyo, 113-8654
So Kato, Prof
India1 site, 1 recruiting
- Recruiting
Kothari Medical Centre
Kolkata
Saumayajit Basu, MD, saumyajitbasu@hotmail.com
Spain1 site, 1 recruiting
- Recruiting
Hospital Vall d´Hebron
Barcelona, 08035
Ferran Pellisé, MD, 24361fpu@comb.es
Turkey (Türkiye)1 site, 1 recruiting
- Recruiting
Acibadem Maslak Hospital
Istanbul
Caglar Yilgor, MD, caglaryilgor@gmail.com
Ahmet Alanay, aalanay@gmail.com
About this study
Official title: Durability of Supplementary Rod Constructs-SuppleMentAry Rod Technique (SMART)-for Long-segment Posterior Instrumented Spinal Fusion Procedures: A Multicenter Retrospective Comparative Study With Dual-rod Constructs
This is a multicenter retrospective comparative cohort study. The index surgery for this study is primary or revision long-segment posterior thoracolumbar (TL) instrumented fusion using either a supplementary rod construct or a dual-rod construct. Eligible patients who already had index surgery, will be identified for enrollment through a review of medical records of the participating surgeons at the study sites.
Read the detailed description
This multicenter retrospective comparative cohort study will enroll 1244 patients, who underwent primary or revision long-segment posterior thoracolumbar (TL) instrumented fusion using either a supplementary rod construct or a dual-rod construct. By comparing two groups of patients, ie, patients treated with supplementary rod constructs vs dual-rod constructs, in the setting of long-segment posterior instrumented spinal fusion, this study aims to provide quality evidence regarding the benefits of supplementary rod constructs in reducing the risk of RFs and other mechanical complications. This study shall provide the first long-term clinical evidence on clinical outcome and benefit of supplementary rod constructs.
All participating surgeons will be asked to identify a time point, denoted as X, when they started using predominantly either supplementary rod constructs or dual-rod constructs for long-segment posterior TL instrumented spinal fusion. This time point X must be on or before December 31, 2020 (the last eligible date for the index surgery). Participating surgeons will be instructed to select the time point X to be as early within the collection window as feasible to maximize the available FU period.
Once the time point X is identified for a participating surgeon, medical records of patients treated by this surgeon will be reviewed to identify consecutive eligible patients with the index surgery done between the time point X and December 31, 2020, inclusive. In the case that an eligible patient had undergone several surgeries during this period, the first primary or revision of long-segment posterior TL instrumented fusion using either a supplementary rod construct or a dual-rod construct is defined as the index surgery.
Patients will then be grouped based on the rod constructs into either the supplementary rod construct group or dual-rod construct group.
The study has two FU periods:
- The first FU period is the first 2 years after the index surgery. The primary analysis will be done using data from the first 2 years of FU.
- The second FU period ends on December March 31, 20232024. The duration of this FU therefore ranges from 3 years and 3 months to 10 years and 3 months.
The primary study endpoint is the occurrence of the first RF within 2 years after the index surgery.
- Conditions
- Spinal Fusion
- Being tested
- long-segment posterior TL instrumented fusion
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
long-segment posterior TL instrumented fusionProcedure or surgery
long-segment posterior TL instrumented fusion with either supplementary rod constructs or dual-rod constructs.
| Study group | Role | What they receive |
|---|---|---|
| primary/revision long-segment posterior TL instrumented fusion with dual-rod constructs | The index surgery for this study is the primary or revision of long-segment posterior TL instrumented fusion using dual-rod construct. Receives: Procedure: long-segment posterior TL instrumented fusion | |
| primary/revision long-segment posterior TL instrumented fusion with supplementary rod constructs | The index surgery for this study is the primary or revision of long-segment posterior TL instrumented fusion using either a supplementary rod construct. Receives: Procedure: long-segment posterior TL instrumented fusion |
What is being measured
The primary outcome is the main question the study is designed to answer.
Rod fracture (RF)
Incidence of rod fracture(s)
Measured: 2 years
Secondary outcomes (7)
Time to rod fracture
Time to the first rod fracture after index surgery
Measured: 2 years
Time to rod fracture
Time to the first rod fracture after index surgery
Measured: 10 years and 3 months
Configurations of supplementary rod constructs
Descriptions of configurations of supplementary rod constructs
Measured: Baseline
Treatment for rod fracture
Descriptions of different treatment strategies for rod fractures
Measured: 10 years and 3 months
Recurrent RFs
Incidence of recurrent rod fractures
Measured: 10 years and 3 months
Other mechanical failures
Other mechanical failures other than rod fractures
Measured: 10 years and 3 months
Surgical complications
Selective surgical complications
Measured: 10 years and 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Apr 2024
- Study start24 Mar 2025
- Primary completion15 Dec 2027 (estimated)
- Study completion31 Jul 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Spinal FusionStudies 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
- Retrospective
- Enrolment
- 1,244 participants (estimated)
Sponsor and investigators
- Lead sponsor
- AO Foundation, AO Spine
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Justin S Smith, MD, PhD, Principal investigator, Professor of Neurosurgery Chief of Spine Division, Fellowship Director University of Virginia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06368245
- Sponsor's protocol ID
- SMART
- Status last verified
- Sep 2026
- First submitted
- 20 Mar 2024
- Last updated
- 1 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 1 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Durability of Supplementary Rod Constructs-SuppleMentAry Rod Technique (SMART)-for Long-segment Posterior Instrumented Spinal Fusion Procedures: A Multicenter Retrospective Comparative Study With Dual-rod Constructs
- ClinicalTrials.gov ID
- NCT06368245
- Acronym / sponsor ID
- SMART
- Conditions
- Spinal Fusion
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 1,244 participants (estimated)
- Lead sponsor
- AO Foundation, AO SpineUniversity, hospital or other
- Study start
- 24 Mar 2025 (actual)
- Primary completion
- 15 Dec 2027 (estimated)
- Study completion
- 31 Jul 2029 (estimated)
- First posted
- 16 Apr 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a multicenter retrospective comparative cohort study. The index surgery for this study is primary or revision long-segment posterior thoracolumbar (TL) instrumented fusion using either a supplementary rod construct or a dual-rod construct. Eligible patients who already had index surgery, will be identified for enrollment through a review of medical records of the participating surgeons at the study sites.
Detailed description
This multicenter retrospective comparative cohort study will enroll 1244 patients, who underwent primary or revision long-segment posterior thoracolumbar (TL) instrumented fusion using either a supplementary rod construct or a dual-rod construct. By comparing two groups of patients, ie, patients treated with supplementary rod constructs vs dual-rod constructs, in the setting of long-segment posterior instrumented spinal fusion, this study aims to provide quality evidence regarding the benefits of supplementary rod constructs in reducing the risk of RFs and other mechanical complications. This study shall provide the first long-term clinical evidence on clinical outcome and benefit of supplementary rod constructs.
All participating surgeons will be asked to identify a time point, denoted as X, when they started using predominantly either supplementary rod constructs or dual-rod constructs for long-segment posterior TL instrumented spinal fusion. This time point X must be on or before December 31, 2020 (the last eligible date for the index surgery). Participating surgeons will be instructed to select the time point X to be as early within the collection window as feasible to maximize the available FU period.
Once the time point X is identified for a participating surgeon, medical records of patients treated by this surgeon will be reviewed to identify consecutive eligible patients with the index surgery done between the time point X and December 31, 2020, inclusive. In the case that an eligible patient had undergone several surgeries during this period, the first primary or revision of long-segment posterior TL instrumented fusion using either a supplementary rod construct or a dual-rod construct is defined as the index surgery.
Patients will then be grouped based on the rod constructs into either the supplementary rod construct group or dual-rod construct group.
The study has two FU periods:
- The first FU period is the first 2 years after the index surgery. The primary analysis will be done using data from the first 2 years of FU.
- The second FU period ends on December March 31, 20232024. The duration of this FU therefore ranges from 3 years and 3 months to 10 years and 3 months.
The primary study endpoint is the occurrence of the first RF within 2 years after the index surgery.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| primary/revision long-segment posterior TL instrumented fusion with dual-rod constructs | – | Procedure: long-segment posterior TL instrumented fusionThe index surgery for this study is the primary or revision of long-segment posterior TL instrumented fusion using dual-rod construct. |
| primary/revision long-segment posterior TL instrumented fusion with supplementary rod constructs | – | Procedure: long-segment posterior TL instrumented fusionThe index surgery for this study is the primary or revision of long-segment posterior TL instrumented fusion using either a supplementary rod construct. |
Who may qualify
- Ages
- 45 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Patients who underwent long-segment posterior thoracolumbar (TL) instrumented fusion
Key inclusion criteria (11 listed)
- Age 45 years and older.
- Patients receiving long-segment posterior TL instrumented fusion using either supplementary rod constructs or dual-rod constructs (the index surgery).
- If the index surgery is a revision surgery, the primary rods must be replaced in the revision surgery, with the exception of Harrington or Luque rods which can remain in place.
- o If the Harrington or Luque rods remain in situ, they must already have the UIV at the thoracic level and the LIV at the sacrum/ilium, or an extension of the existing Harrington or Luque is performed such that the UIV is at the thoracic level and the LIV at the sacrum/ilium.
- The index surgery was performed between January 1, 2014, and December 31, 2020, inclusive.
Key exclusion criteria (6 listed)
- Spinal fusion performed for acute trauma (ie, ≤ 1 year of trauma).
- Spinal fusion performed for tumor.
- Spinal fusion performed for infection.
- Patients with Parkinson's Disease.
- Patients with neuromuscular disorders.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| long-segment posterior TL instrumented fusionlong-segment posterior TL instrumented fusion with either supplementary rod constructs or dual-rod constructs. | Procedure or surgery | primary/revision long-segment posterior TL instrumented fusion with dual-rod constructs, primary/revision long-segment posterior TL instrumented fusion with supplementary rod constructs |
Primary outcome
Rod fracture (RF)
Time frame: 2 years
Incidence of rod fracture(s)
7 secondary outcomes
Time to rod fracture
Time frame: 2 years
Time to rod fracture
Time frame: 10 years and 3 months
Configurations of supplementary rod constructs
Time frame: Baseline
Treatment for rod fracture
Time frame: 10 years and 3 months
Recurrent RFs
Time frame: 10 years and 3 months
Other mechanical failures
Time frame: 10 years and 3 months
Surgical complications
Time frame: 10 years and 3 months
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Oct 2026.
- Individual participant dataSharing planned: Undecided
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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.
Justin S Smith, MD, PhD principal investigator
Professor of Neurosurgery Chief of Spine Division, Fellowship Director University of Virginia
17 sites in 7 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Spinal Fusion, run by AO Foundation, AO Spine at 17 sites in 7 countries.
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 11 inclusion and 6 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: looking for participants now, as of the sponsor's last update on 1 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 17 sites in United States, Canada, Japan, China, India and 2 more countries. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Alix Frischknecht (+41 79 606 41 48, alix.frischknecht@aofoundation.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rod fracture (RF) (time frame: 2 years). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 1 Oct 2026.