LINQ® Procedure vs. Conventional Medical Management for Sacroiliac Dysfunction (LINQT)

LINQT: An Open Label Randomized, Controlled, Multicenter, Prospective, Long Term Clinical Study on the Minimally Invasive Posterior Sacroiliac Fusion Device LINQ® System

The objective of this clinical evaluation is to assess the safety and effectiveness of LINQ fusion procedure for treatment of sacroiliac joint (SIJ) dysfunction compared to Conservative Medical Management (CMM).

Study Overview

• Status: Not yet recruiting
• Conditions: Sacroiliac Joint Pain
• Intervention / Treatment: Procedure: Bone Allograft; Other: Conventional Medical Management (CMM)

Detailed Description

Prospective, multi-center, open-label, randomized, clinical study. Subjects who meet the eligibility criteria and are enrolled will be randomized 2:1 to LINQ or CMM. After their 6 Month evaluations are complete, subjects in the Control Group can elect to stay in the CMM Arm or crossover to receive the LINQ procedure.

Each subject will undergo a Screening Visit, Randomization, Baseline Procedure or CMM Initiation Visit, and Follow-Up Visits through 24 Months. The primary endpoint is evaluated at the 6 Month Follow Up Visit.

Subjects that elect to crossover from the Control Group to the Treatment Group at the 6 Month Visit, will have Procedure and Follow-Up Visits through 18 Months post crossover procedure.

• Study Type: Interventional
• Enrollment (Estimated): 200
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Lalit Venkatesan, PhD; Phone Number: 18552487246; Email: lalit.venkatesan@painteq.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• To be eligible to participate in this study, a subject must meet ALL of the following criteria, as determined by the Investigator:

  1. Age and Body Mass Index (BMI)

     1. Adult subjects aged ≥ 21 years at screening.
     2. BMI ≤ 40.

  2. Chronic SIJ-Related Pain

     1. Has experienced low back and/or buttock pain for at least 6 months that has been inadequately responsive to non-surgical management.
     2. Has experienced nonradicular pain that is maximal below the L5 vertebrae, localized over the posterior SIJ, and consistent with SIJ pain.

  3. Diagnosis of SIJ Dysfunction

     a. Has a diagnosis of SIJ dysfunction (degenerative sacroiliitis or SIJ disruption) based on ALL of the following: i. A positive Fortin's finger test; and ii. Pain elicited at least three (3) of five (5) SIJ-specific physical examination maneuvers (FABER test, Gaenslen's test, Distraction, Thigh Thrust, Compression); and iii. At least 75% reduction in pain, with associated improvement in previously painful maneuvers, for the expected duration of action following two (2) image-guided, contrast-enhanced intra-articular diagnostic SIJ injections, performed on separate visits using anesthetics with different durations of action; and iv. Completion of at least one (1) therapeutic intra-articular SIJ injection (e.g., corticosteroid injection) within the past 12 months.

  4. Baseline Disability and Pain Severity

     a. Baseline Oswestry Disability Index (ODI) score ≥30%; and b. Baseline SI joint pain score of ≥60 mm on a 100 mm Visual Analog Scale (VAS).

  5. Nicotine Abstinence

     a. Is able and willing to completely avoid all forms of nicotine (including smoking, vaping, e-cigarettes, tobacco, or nicotine pouches) for the entire duration of the study.

  6. Treatment Decision

     a. The treating physician has independently determined that the LINQ procedure is an appropriate treatment option for the subject's SIJ dysfunction in the course of routine clinical care, and the subject has agreed to undergo this treatment.

  7. Informed Consent and Compliance

     1. Is willing and capable of providing written informed consent; and
     2. Is willing and able to comply with all study-related requirements, procedures, and follow-up visits.

Exclusion Criteria:

• Exclusion Criteria Subjects must meet none of the following criteria to be eligible for participation in this study, as determined by the Investigator:

  1. Pain Source Uncertainty a. Inability to confirm, in the Investigator's clinical judgment, that the subject's primary pain generator is the sacroiliac joint.

  2. Alternative Primary Spine Pathology

     a. Presence of severe low back pain attributable to other spinal pathology, including but not limited to lumbar disc degeneration, lumbar disc herniation, lumbar spondylolisthesis, lumbar spinal stenosis, lumbar facet degeneration, or lumbar vertebral body fracture.

  3. Other Sacroiliac Pathology

     a. Presence of known sacroiliac joint pathology other than degenerative SIJ dysfunction, including inflammatory sacroiliitis (e.g., ankylosing spondylitis or other HLA-associated spondyloarthropathies), tumor, infection, acute fracture, or crystal arthropathy.

  4. Non-SIJ Pain Syndromes

     a. History of coccydynia or prior coccygectomy, endometriosis, cluneal neuralgia, or pudendal neuralgia.

  5. Recent Sacral Interventions

     a. Prior sacral radiofrequency ablation performed within 6 months prior to enrollment.

  6. Recent Pelvic Trauma

     a. History of major pelvic trauma within 12 months prior to enrollment.

  7. Severe Osteoporosis

     a. Prior diagnosis or suspicion of severe osteoporosis, defined as a prior bone mineral density T-score of < -2.5 or a history of osteoporotic fracture.

  8. Medications Detrimental to Bone or Soft-Tissue Healing

     a. Current use of medications known to adversely affect bone quality or soft-tissue healing, as determined by the Investigator.

  9. Anatomic Constraints

     a. Anatomic anomalies or defects that, in the Investigator's opinion, would preclude safe or biomechanically appropriate device placement.

  10. Systemic Inflammatory or Rheumatologic Disease

      a. Presence of a chronic inflammatory rheumatologic condition, such as rheumatoid arthritis.

  11. Centralized Pain Syndromes

      a. Current diagnosis of fibromyalgia.

  12. Infection Risk

      a. Evidence of current local or systemic infection that would increase surgical risk.

  13. High-Dose Opioid Therapy (≥90 MME/day)

      a. Current use of systemic opioid analgesics at Screening/Baseline with an average daily dose ≥90 morphine milligram equivalents (MME/day), based on medication reconciliation (prescription records and subject report) and standard MME conversion factors.

  14. Current Nicotine Use (Self-Reported)

      a. Self-reported use of any nicotine-containing products (including smoking, vaping/e-cigarettes, cigars, pipes, smokeless tobacco, nicotine pouches, and nicotine replacement products) within 6 weeks prior to Screening/Baseline.

  15. Secondary Gain or Litigation

      a. Currently receiving or actively seeking workers' compensation or disability benefits or involved in injury-related litigation.

  16. Pregnancy

      a. Currently pregnant or planning to become pregnant within two (2) years following enrollment, as self-reported.

  17. Vulnerable Populations

      a. Individuals who are prisoners or wards of the state.

  18. Substance Abuse

      a. Known or suspected active drug or alcohol abuse, including opioid misuse.

  19. Psychiatric Conditions

      a. Diagnosed psychiatric disorder (e.g., schizophrenia, major depressive disorder, personality disorder) that, in the Investigator's judgment, could interfere with study participation.

  20. Concurrent Interventional Research

      a. Current participation in another clinical trial.

  21. Neurologic Conditions Affecting Rehabilitation

      a. Presence of a significant neurologic disorder that would interfere with participation in physical therapy or post procedural rehabilitation.

  22. Other Confounding Medical Conditions a. Any other medical condition or pain condition not intended to be treated in this study that, in the Investigator's judgment, could interfere with study procedures, accurate pain reporting, or interpretation of study endpoints.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Treatment Arm (LINQ Procedure); Subjects randomized to the Treatment Arm will undergo the LINQ Procedure.	Procedure: Bone Allograft; The LINQ system is intended for use in patients with SIJ disease by implantation of compatible implants to prepare the SIJ for allograft fusion.
Active Comparator: Conventional Medical Management (CMM); Subjects randomized to the CMM Control Arm shall receive standardized, stepwise, non-surgical management for SIJ pain.	Other: Conventional Medical Management (CMM); CMM Control Arm shall receive standardized, stepwise, non-surgical management for SIJ pain.; Other Names: Non-Surgical Management

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Composite Success Responder Rate at Month 6	Unit of Measure: Percentage of participants Description: The primary endpoint is a single binary (Yes/No) composite responder classification per subject at Month 6. A subject is classified as a composite success responder ONLY if ALL three of the following criteria are met: Pain Improvement: Reduction in SIJ pain VAS score of ≥20 mm from baseline to Month 6 (VAS measured on 0-100 mm scale). Safety: Absence of any device-related or procedure-related SAEs through Month 6 (Day 180). Surgical Reintervention: No surgical reintervention for SIJ fusion through Month 6 (Day 180), including device removal (complete or partial), device revision or replacement, or reoperation at the index SIJ. Subjects meeting all three components are classified as responders; the outcome is reported as the percentage (%) of participants classified as responders.	Month 6

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual Analog Scale (VAS)	The Visual Analog Scale (VAS) is a patient-reported measure of pain intensity assessed using a 100 mm horizontal line anchored by 0 mm ("no pain") and 100 mm ("worst imaginable pain"). Scores range from 0 to 100 mm, with higher scores indicating greater pain severity. Change from baseline in VAS score and proportion of participants achieving a minimum clinically important difference (MCID) in pain intensity will be assessed. MCID is defined as a reduction of ≥20 mm from baseline on the 0-100 mm scale. Higher proportions indicate greater clinical improvement.	Months 1, 3, 6, 12, 18, 24.
Oswestry Disability Index (ODI)	The Oswestry Disability Index (ODI) is a validated patient-reported questionnaire assessing disability related to low back pain across 10 domains of daily living. Scores range from 0 to 100, with higher scores indicating greater disability. Change from baseline in ODI score and proportion of participants achieving a minimum clinically important difference (MCID) in disability will be assessed using the Oswestry Disability Index (ODI). MCID is defined as a reduction of ≥15 points from baseline on the 0-100 scale. Higher proportions indicate greater clinical improvement.	Months 1, 3, 6, 12, 18, 24
Patient-Reported Outcomes Measurement Information System (PROMIS-29+2)	The Patient-Reported Outcomes Measurement Information System 29-Item Profile v2.1 + 2 (PROMIS-29+2) assesses multiple health domains including physical function, anxiety, depression, fatigue, sleep disturbance, ability to participate in social roles, pain interference, and cognitive function. Domain scores are reported as T-scores standardized to a mean of 50 and standard deviation of 10 in the general population, with a typical range of approximately 20 to 80. Higher scores indicate more of the domain being measured (e.g., worse symptoms for anxiety, depression, fatigue, sleep disturbance, pain interference, and cognitive concerns; and better functioning for physical function and social participation). Change from baseline in T-scores will be evaluated.	Months 1, 3, 6, 12, 18, 24
EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire	The EuroQol 5-Dimension 5-Level (EQ-5D-5L) questionnaire is a standardized measure of health-related quality of life assessing five domains: mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Responses are converted into a single index score using country-specific value sets. The index score typically ranges from less than 0 (health states worse than death) to 1 (perfect health), where higher scores indicate better health status. Change from baseline in EQ-5D-5L index scores will be evaluated.	Months 1, 3, 6, 12, 18, 24
Patient Global Impression of Change (PGIC)	The Patient Global Impression of Change (PGIC) is a patient-reported measure assessing overall change in health status since the start of treatment. It is a 7-point ordinal scale with responses ranging from 1 ("very much improved") to 7 ("very much worse"). Lower scores indicate greater improvement, and higher scores indicate worsening. The distribution of PGIC responses across categories will be summarized.	Months 1, 3, 6, 12, 18, 24
Medication use	Medication use will be assessed at each visit, including opioid and non-opioid pain medications. Opioid consumption will be quantified as daily morphine milligram equivalents (MME), calculated using standard conversion factors. MME values range from 0 upward, with higher values indicating greater opioid use. Change from baseline in daily MME will be evaluated. Additional analyses may include the proportion of participants reducing or discontinuing opioid use over time.	Months 1, 3, 6, 12, 18, 24
Healthcare Resource Utilization (HCRU)	Healthcare Resource Utilization (HCRU) will be assessed at each visit and may include the number of healthcare encounters such as outpatient visits, emergency department visits, hospitalizations, interventional pain procedures, and other pain-related medical services. Utilization will be summarized as counts and cost per participant over time, with higher values indicating greater healthcare utilization.	Months 1, 3, 6, 12, 18, 24

Collaborators and Investigators

• Sponsor: PainTEQ, LLC

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): December 1, 2027
• Study Completion (Estimated): July 1, 2029

Study Registration Dates

• First Submitted: April 23, 2026
• First Submitted That Met QC Criteria: April 23, 2026
• First Posted (Actual): April 30, 2026

Study Record Updates

• Last Update Posted (Actual): May 15, 2026
• Last Update Submitted That Met QC Criteria: May 13, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: sacroiliac joint dysfunction; LINQ
• Other Study ID Numbers: PTQ-002

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Sponsored Study

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No