Prognostic Factors in Zygapophyseal Osteoarthritis Infiltration: a Prospective Cohort Study

Magnet Resonance Image findings of facet osteoarthritis and patient characteristics are prognostic factors for improving or worsening the clinical outcome after treatment with facet infiltration.

Inclusion criteria The following are inclusion criteria for participants: * Older than 18 years; * Fluent or native Portuguese language speaker; * Continuous or intermittent low back pain for at least three months; * Low back pain with or without irradiation to the gluteal region indicating facet syndrome (pain is aggravated by spine extension or bending toward the affected side; pain is exacerbated by prolonged sitting or walking up steps, as well as retaining one position for a prolonged time); * Failure of traditional treatment includes, but is not limited to, physical or drug therapy; * Understand the purpose of the study; * Voluntarily provide a free and informed consent form, by themselves or through their partners, and complete the questionnaires, before undergoing infiltration, over the telephone or online during the follow-up. Exclusion criteria The following are exclusion criteria for participants: * Younger than 18 years old, * Symptomatic lumbar spinal stenosis with claudication or radiculopathy; * Evidence of radiculopathy; * Active rheumatologic diseases; * Congenital or acquired deformities of the lumbar spine; * Fracture or sequel of lumbar spine fracture of traumatic, pathological or osteoporotic origin; * Surgical manipulation of the lumbar spine; * MRI scans of limited quality and incomplete sequences; * Treated with systemic steroids less than one month before the IFI; * Treated with IFI with steroids within the last six months; * Diagnosed with uncontrolled diabetes mellitus; * History of allergy to anesthetics or adverse reaction to steroids; * Pregnant women or women who breastfed; * Who could not be contacted over the phone during follow-up.