cyst in the spine arises from a spinal (facet) joint. The joint is usually
degenerative. The fluid level expands in the involved spinal joint causing the
lining of the joint (synovium) to expand to accommodate the increased pressure.
This results in an extension of the synovium away from the outer border of the
facet joint complex. Facet cysts usually project in an anterior and medial
direction. This places the cyst in the spinal canal and/or within the
neuroforamen, which refers to an opening along the side of the spine where the
spinal never traverses.
synovial cysts are more common in individuals over 60 years old. They occur more
commonly in females. There is no racial predilection. They are most likely to
develop at the site of a degenerative spinal joint.