Clinical Study on a Novel Minimally Invasive Posterior Sacroiliac Fusion Device

Inclusion Criteria: * Age 21-70 * Patient has lower back pain for \>6 months inadequately responsive to conservative care * Patient has at least 3 of 4 physical examination maneuvers specific for the SI joint (FABER, Gaenslen test, Stork/Gillete, and Yoman) * Patient has improvement in lower back pain numeric rating scale (NRS) of at least 50% after injection of local anesthetic into affected SI joint(s) with confirmed arthrogram, within 30-60 min from injection * Degenerative sacroiliitis as SIJ mediated in in the context of either radiographic evidence of SIJ degeneration, evident on computed tomography or Xrays or a history of prior lumbar fusion. * SIJ disruption was defined in the study of as SIJ mediated pain in the context of asymmetric widening of SIJ on CT or Xrays or the presence of significant contrast leakage during diagnostic SIJ block * Baseline Oswestry Disability Index (ODI) score of at least 30% * Baseline Low back/buttock pain score of at least 50 on 0-100 mm visual analog scale * Patient has signed study-specific informed consent form * Patient has the necessary mental capacity to consent and participate and is physically able to comply with study protocol requirements * Patient has medical insurance that covers this standard of care procedure and all other anticipated and unanticipated procedure related care. * Patient's physician has decided that the best treatment for the patient's sacro-iliac disease is the LinQ system and the patient has agreed to the treatment. Exclusion Criteria: * Inability to confirm that the pain is arising from the sacroiliac joint * 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 * SIJ pain secondary to inflammatory conditions, 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. * Radicular pain extending beyond the buttock ≥ 30mm on VAS * Has complete resolution of pain from the diagnostic SIJ injection lasting 30 days or more * Has had an injection with corticosteroid into the index SIJ within the last 90 days * Has had any neuraxial injection with corticosteroid within the last 90 days * Has greater than 50% pain relief from diagnostic medial branch bl…