Facet Arthritis

Facet joints are formed by the articulations of the superior and inferior articular processes of adjacent vertebrae. Except for the atlantooccipital and atlantoaxial joints, facet joints are lined with synovium and covered by a true joint capsule. The capsule is richly innervated. Each facet joint receives innervation from two spinal levels, one of which is from the dorsal ramus at the same vertebral level and the other of which is from one level above. This explains why facet-related pain is not easy to locate.