Tenon Medical CATAMARAN™ SI Joint Fusion System CT Scan Study

Inclusion Criteria:

• Patient >18 years of age at time of treatment with the CATAMARAN SI Joint FusionSystem
• Patient implanted with the CATAMARAN Fixation Device within the last 12 months
• Diagnosis of sacroiliac joint disruption or degenerative sacroiliitis
• Patient, or authorized representative, signs a written Informed Consent form toparticipate in the study
• Patient is willing and able to complete study follow-up requirements

Exclusion Criteria:

• Known or suspected active drug or alcohol abuse
• Previously diagnosed osteoporosis (defined as prior T-score <-2.5 or history ofosteoporotic fracture) or prior/current use of drug therapy for osteoporosis.
• Prior fracture of any bone related to cancer/tumor (i.e., pathologic fracture)
• Prior diagnosis of tumor in sacrum or ilium
• Unstable fracture of sacrum and or ilium involving the targeted SIJ
• Osteomalacia or other metabolic bone disease
• Use of medications known to have detrimental effects on bone quality and soft-tissuehealing
• Patient is pregnant or wishes to become pregnant during the study period
• Patient is not likely to comply with the follow-up evaluation schedule
• Patient is a prisoner or a ward of the state