The facet, or zygapophyseal, joints come in pairs between each level of the spine. The superior articular process rises from the lower verte-brae and an inferior process descends from the vertebrae above it. These meet in the lumbar spine at an oblique angle from anteromedial to posterolateral to form a true synovial joint. Facet degeneration can occur due to repetitive lumbar extension stress or as part of the "degenerative cascade” of the lumbar spine, beginning with disc annular tears, bulging, and desiccation, leading to loss of disc height and increased load bearing on the facet joints. Pain from the facet joint accounts for up to 15% of chronic low back pain, usually axial, but lower lumbar facets in particular can radiate distally into the groin, flank, hip, lateral thigh, and even the lateral leg and foot, thus mimicking a radiculopathy.  No history or physical examination findings can credibly point to the facet as the source of a patient's symptoms or reliably predict a good response to facet injections. There is also no clear consensus or gold standard diagnostic test that identifies a facet joint as the source of symptoms as well as no sufficient evidence to support the routine use of imaging in the diagnosis of lumbar facets as a source of symptoms.  Both fluoroscopically-guided intra-articular facet injections or injections around the medial branch of the posterior ramus are frequently used for both diagnostic and therapeutic purposes, though the weight of evidence supports the medial branch block as the more useful. However, aberrant or redundant anatomy, technical error, placebo effect, or spillover of injectate into adjacent pain-generating structures can lead to false positive and false negative results for both of these procedures.  In addition to facet-related procedures, anti-inflammatories, oral analgesics, and physical therapy are used to treat facet syndrome.