LINQ® Procedure vs. Conventional Medical Management for Sacroiliac Dysfunction

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.

Proportion of Participants Achieving Both a ≥20 mm Reduction in SIJ Pain VAS and a ≥15 Point Reduction in ODI

Composite responder analysis based on two validated patient-reported outcomes. Pain intensity is measured using a 100 mm Visual Analog Scale (VAS) anchored by 0 mm ("no pain") and 100 mm ("worst imaginable pain"); higher scores indicate greater pain severity. Disability is measured using the Oswestry Disability Index (ODI), a 10-item questionnaire assessing low back pain-related disability across domains of daily living, scored 0-100; higher scores indicate greater disability. A participant is classified as a responder if they achieve BOTH a reduction of ≥20 mm from baseline in sacroiliac joint (SIJ) pain VAS AND a reduction of ≥15 points from baseline in ODI. The proportion of responders will be reported and a higher proportion indicates greater clinical improvement.

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.

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.

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.

Characterization of Procedure Details and Healthcare Utilization

Supportive data will be collected to characterize the index procedure and subsequent healthcare utilization. Procedure details include procedure time, anesthesia type, fluoroscopy time, and technical success. Healthcare utilization includes pain-related medication use, injections, additional interventions or reoperations, and pain-related healthcare visits from baseline through study completion. Data will be summarized descriptively.