An apophyseal joint is a point where two or more bones join in the spine.
The spinal joint is encapsulated by connective tissues, coated with cartilage and lubricated with synovial fluid to enable smooth joint articulation. Each vertebra has a pair of apophyseal joints- one on the left and one on the right. Each joint is composed of a superior articular facet joint that faces up and an inferior articular facet that faces down.
Apophyseal joints are hinge-like joints that allow the flexion, extension and torsion of the spine. These joints also interlock the vertebra to make the spine more stable.