Sacroiliac (SI) Joint Transfixing and Fusion: Meaningful Long Term Outcomes With Nevro1 (SIMON1)

June 23, 2026 updated by: Nevro Corp

A Post-market, Multicenter, Prospective, Clinical Study to Evaluate the Nevro1 Sacroiliac (SI) Transfixing and Fusion System for the Treatment of Sacroiliac Joint Dysfunction

The goal of this observational study is to learn if Nevro1 Sacroiliac Transfixing and Fusion System can treat sacroiliac joint dysfunction in males or females over 21. The main questions it aims to answer is what percentage of patients have clinically important pain relief with no adverse events, and what proportion of patients have fusion of the sacroiliac joint at 1 year and 2 years.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
180

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Lodi, California, United States, 95240
        • AIRS Clinic
    • Michigan
      • Southfield, Michigan, United States, 48033
        • Michigan Orthopaedic Surgeons
    • North Carolina
      • Winston-Salem, North Carolina, United States, 27103
        • Carolinas Pain Institute
    • Texas
      • Spring, Texas, United States, 77380
        • Advanced Spine and Pain Specialists
      • The Woodlands, Texas, United States, 77384
        • Procura Pain and Spine

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Cohort will be selected from participating clinics

Description

Inclusion Criteria:

  1. Has medical insurance that covers this standard of care procedure and all other anticipated and unanticipated procedure-related care, and all coverage criteria required by insurer are met, which may include but are not limited to:

    • Has had low back and/or buttock pain for at least 6 months that is inadequately responsive to non-surgical care
    • Has a positive Fortin's test
    • Has a diagnosis of SIJ dysfunction (degenerative sacroiliitis or SI disruption) with pain elicited on at least 3 of 5 provocative tests (FABER, Gaenslen, Distraction, Thigh Thrust, Compression).
    • At least 75% reduction in pain for the expected duration of two anesthetics (on separate visits each with a different duration of action), and the ability to perform previously painful maneuvers, following an image-guided, contrast-enhanced intra-articular (diagnostic) SIJ injection
    • A trial of at least one therapeutic intra-articular SIJ injection (i.e. corticosteroid injection)
  2. Has an ODI score ≥30% at enrollment
  3. Has a SI joint pain score of at least 5 out of 10 on numerical rating scale at enrollment.
  4. Be at least 21 years of age at enrollment
  5. The patient's physician has decided that the best treatment for the patient's SIJ dysfunction is the Nevro1 SI Fixation System, and the patient has agreed to the treatment
  6. Be willing and capable of giving written informed consent
  7. Be mentally and physically able to comply with study-related requirements and procedures and attend all scheduled visits

Exclusion Criteria:

  1. Has current severe back pain due to other causes, such as lumbar disc degeneration, lumbar disc herniation, lumbar spondylolisthesis, lumbar spinal stenosis, lumbar facet degeneration, lumbar radicular pain, and lumbar vertebral body fracture
  2. Has SIJ pain secondary to inflammatory conditions or other known sacroiliac pathology such as: Sacral dysplasia, inflammatory sacroiliitis (e.g., ankylosing spondylitis or other HLA-associated spondylo-arthropathy), tumor, infection, acute fracture, and crystal arthropathy
  3. Has had a previous SIJ implant placement, including an allograft
  4. Has had an injection with corticosteroid into the index SIJ within the last 30 days
  5. Has had a sacral radiofrequency ablation within the last 6 months
  6. Has a history of recent (<1 year) major trauma to pelvis
  7. Has previously diagnosed or suspected severe osteoporosis (defined as prior T-score < -2.5 or history of osteoporotic fracture)
  8. Has a chronic rheumatologic condition (e.g., rheumatoid arthritis)
  9. Has a known allergy to titanium or titanium alloys
  10. Has a current local or systemic infection that raises the risk of surgery
  11. Is currently receiving or seeking short- or long-term worker's compensation related to the SI joint or low back pain, is currently receiving disability remuneration related to SI joint or low back pain, and/or is currently involved in injury litigation related to the SI joint or low back pain
  12. Is participating in an investigational study or has been involved in an investigational study within 3 months prior to enrollment
  13. Has any condition or anatomy that makes treatment with the Nevro1 SI Fixation System infeasible
  14. Is taking a medication known to have detrimental effects on bone quality and soft tissue healing
  15. Has a prominent neurologic condition that would interfere with physical therapy
  16. Be pregnant or plan on becoming pregnant in the next two years.
  17. Has a medical condition or pain in other area(s), not intended to be treated in this study, that could interfere with study procedures, accurate pain reporting, and/or confound evaluation of study endpoints, as determined by the Investigator

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Treated Group
Treated with Nevro1 transfixing and fusion system
Device: Sacroiliac Joint transfixing and fusion system (Nevro1)
The Nevro1 is a titanium cage the is implanted in the sacroiliac join from a posterior direction, and then anchors are deployed that stabilize the joint. It has multiple openings to allow surgeons to fill them with autogenous bone graft to encourage bone bridging through the implant for SIJ fusion.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Composite Pain Relief and Safety Responder
Time Frame: 6 months

The proportion of patient meeting the following criteria:

  • NRS score for SIJ pain reduced by at least 2 points from baseline.
  • Absence of implant-related serious adverse events (SAEs).
  • Absence of neurologic worsening related to the lumbosacral nerve roots.
  • Absence of reoperation (removal, revision reoperation or supplemental fixation) for SIJ pain.
6 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Timed "Up and Go" Performance test (TUG)
Time Frame: 6 months
Absolute change from baseline in time to perform the TUG.
6 months
Change in Disability
Time Frame: 6 months
Absolute change from baseline in Oswestry Disability Index (ODI) score. The total score ranges from 0 (minimal disability) to 100 (severe disability, e.g., bedridden).
6 months
Patient Global Impression of Change (PGIC)
Time Frame: 6 months
Proportion of patients reporting "Better" or "A great deal better" on the PGIC. The PGIC is a 7-point scale with responses ranging from "no change (or condition has gotten worse)" to "a great deal better".
6 months
Physical and Mental Health Summary (PROMIS-29)
Time Frame: 6 months
Absolute change from baseline in PROMIS-29 score. Higher scores represent greater impact of pain on a patients life in the domains of physical function, fatigue, pain interference, depressive symptoms, anxiety, ability to participate in social roles and activities, and sleep disturbance.
6 months
Change in Quality of Life
Time Frame: 6 months
Absolute change from baseline in the index score of EuroQol 5-dimension 5 level (EQ-5D-5L) a standardized measure of health status. The index score ranges from zero to one, with one representing the highest possible health state.
6 months
Change in Sleep Disturbance Due to Pain
Time Frame: 6 months
Absolute change from baseline in Pain and Sleep Questionnaire Three-Item Index (PSQ-3) score. The scale ranges from 0 (pain does not affect sleep) to 30 (pain has maximum effect on sleep).
6 months

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Presence of bone apposition on implant surface
Time Frame: 12 and 24 months
Grading of the presence of bone apposition on the device adjacent to the sacrum and ilium.
12 and 24 months
Presence of bony fusion across the sacroiliac joint
Time Frame: 12 and 24 months
Grading of the presence of bony fusion across the sacroiliac joint.
12 and 24 months
Presence of radiolucency at the implant surface
Time Frame: 12 and 24 months
Grading of the presence of radiolucency at the device surface adjacent to the sacrum and ilium.
12 and 24 months
Proportion of patients with different levels of treatment response
Time Frame: 3, 6, 12, and 24 months
Evaluating different pain relief response rates, defining responder as a participant who experiences ≥30%, ≥50% and ≥80% pain relief vs. Baseline as measured by NRS.
3, 6, 12, and 24 months
Sub-analysis comparing outcomes between age groups
Time Frame: 3, 6, 12, and 24 months.
All outcomes will be compared between the two age groups: 21 to 70 years, and 71 years and above.
3, 6, 12, and 24 months.
Rate of adverse events
Time Frame: Implant, 1, 3, 6, 12, and 24 months.
Proportion of patients who experience and adverse event related to the procedure or device including infection, device breakage, migration, neurological worsening, and procedural blood loss.
Implant, 1, 3, 6, 12, and 24 months.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Nevro Corp

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Rose P Azalde, MS, Nevro Corp

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 3, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 21, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
May 21, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
March 27, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
March 27, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 3, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
June 25, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 23, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • CA2024-02 US SIJ-PM

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Study data will be reported with descriptive statistics describing group level outcomes, not individual outcomes.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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