Post-Market Feasibility Study of the Tenon Medical CATAMARAN™ SI Joint Fusion System

The purpose of this study is to evaluate the outcomes of patients with sacroiliac joint pain treated with the CATAMARAN SI Joint Fusion System.

Inclusion Criteria:Diagnosis of sacroiliac joint disruption or degenerative sacroiliitis based on ALL of the following:Patient has pain at or close to the posterior superior iliac spine (PSIS) with possible radiation into buttocks, posterior thigh or groin and can point with a single finger to the location of pain (Fortin Finger Test), andPatient has at least 3 of 5 physical examination maneuvers specific for SI joint pain (Fabers, Compression, Distraction,Thigh thrust, Gaenslen's test, and/or Sacral thrust test), andPatient has improvement in lower back pain VAS of at least 50% of the pre injection VAS after fluoroscopic controlled injection of local anesthetic into affected SI joint(s) (including previous documented test <6 months ago)Patient has failed conservative care (non-surgical) > 6 monthsPatient has a pre-operative Oswestry Disability Index score > 30%Patient has a pre-operative SI joint pain score of > 50 on a 0-100 mm visual analog scale (VAS)Patient, or authorized representative, signs a written Informed Consent form to participate in the studyPatient is willing and able to complete study follow-up requirementsExclusion Criteria:Planned bi-lateral SI joint fixationSevere lower back pain due to other causes, such as lumbar disc degeneration, lumbar disc herniation, lumbar spondylolisthesis, lumbar spinal stenosis, lumbar facet degeneration, and lumbar vertebral body fracture (this is done by physical exam, medical history, and MRI/CT/X-ray as required)Other known sacroiliac pathology such as: sacral dysplasia, inflammatory sacroiliitis (e.g., ankylosing spondylitis or other HLA- associated spondyloarthropathy), tumor, acute fracture, crystal arthropathyHistory of recent (<1 year) fracture of the pelvis with documented malunion, non-union of sacrum or ilium or any type of internal fixation of the pelvic ringSevere osteoporosisPaget's disease, osteomalacia, osteomalacia or other metabolic bone diseaseAny condition or anatomy that makes treatment with the CATAMARAN SI Joint Fusion System infeasible including deformityKnown allergy to titanium or titanium alloysMorbid obesityActive malignancy: a history of any invasive malignancy (except non-melanoma skin cancer), unless the subject has been treated with curative intent and there have been no clinical signs or symptoms of the malignancy for at least five yearsPatient has systemic infection or active infection at the treatment siteChronic rheumatologic condition (e.g., rheumatoid arthritis)Patient has uncontrolled diabetesPatient is currently receiving or seeking worker's compensation, disability remuneration, and/or involved in injury litigationProminent neurologic condition that would interfere with physical therapyPatient is pregnant or wishes to become pregnant in the next two yearsPatient is not likely to comply with the follow-up evaluation schedulePatient is participating in a clinical trial of another investigational drug or device in which the primary endpoint has not occurredPatient has a psychiatric disease (e.g., schizophrenia, major depression, personality disorders) that could interfere with study participationKnown or suspected drug or alcohol abusePatient is a prisoner or a ward of the state