Facet joints, or z-joints (zygapophyseal joints), are the paired joints that connect two consecutive vertebrae segments in the spine. They work like any other joints in the body – for stability and for range of motion.
Over time, with aging and physical activity, facet joints degenerate as in leading to osteoarthritis. The pain produced from facet joint arthritis is most common in the neck and back but can also involve shoulders, arms, hips and legs.
Facet injections are performed for pain relief in addition to physical therapy and medications.