SAIF: Sacroiliac Fusion Study

Inclusion Criteria: * Subjects must be indicated for the SImmetry device according to the approved SImmetry labeling * Subject has three (3) positive (experiences pain) Provocative Tests for SIJ pain; for example, Compression, Thigh Thrust, FABER, Distraction or Gaenslen's * Subject has documentation of failed, non-operative management of SIJ pain for ≥ 6 months prior to surgery; for example, use of medications, braces, SI belts, orthotics, physical therapy or manual manipulation * The subject has one (1) positive diagnostic SIJ injection, resulting in a ≥50% decrease in pain from the anesthetic portion of the injection * The subject has VAS back pain score of ≥ 60 mm * The subject has an ODI ≥ 40% * The subject is at least 18 years of age and skeletally mature * The subject agrees and is able to comply with study requirements Exclusion Criteria: * Subjects contraindicated per the cleared labeling will be excluded from participation in the study * The subject has pelvic soft tissue or bony tumors * The subject has had any trauma causing fracture of the sacrum or iliac bones or has had spinal trauma leading to a neurological deficit * The subject has a history of a central nervous system (CNS) disorder(s) * The subject is pregnant or is planning on becoming pregnant in the next two years * The subject has chemical dependency problems as evidenced by a history of drug abuse which is documented in their past medical history or is elicited from an interview * The subject has a history of significant emotional or psychosocial disturbance (anxiety attacks, obsessive/compulsive disorders, depression or schizophrenia) as documented in their past medical history or elicited by an interview