Anterosuperior articular facet from the vertebral body below and is concave
Posteroinferior articular facet from the vertebral body above and is convex
Oriented obliquely to sagittal plane
Joint space is curved from front to back
Covered by hyaline cartilage and have true synovial membrane, and hence involved in rheumatoid arthritis or ankylosing spondylitis.
Articular recesses:
Superior recess: located anteriorly, close to lumbar canal and neural elements, and may extend within intervertebral foramen.
Inferior recess: located posteriorly, no direct contact with neural elements
Increased lordosis widens superior recess, and kyphosis widens inferior recess
Nerve supply:
Rich sensory innervation by recurrent sensory nerve from ipsilateral posterior lumbar ramus at its own level and from the level above
References:
Sarazin L et al. Lumbar Facet Joint Arthrography with the Posterior Approach. Radiographics. 1999;19:93-104
