Ganglion Cysts in the Lumbar Spine Overview
Ganglion cysts can occur in any joint. In fact, many people are aware of these but have never considered what they are. The small round “bumps” that occur under the skin at the wrist are typically ganglion cysts. Some individuals may remember the “Bible treatment” for these developed years ago where someone had the bright idea to smash a Bible onto the wrist to attempt to pop these cysts. This is not a recommended treatment for ganglion cysts in today’s world.
To understand what a ganglion cyst is, we must understand the design of a diarthrodial joint. This type of joint is the junction of two bones (such as the tibia and the femur at the knee). The surfaces of the joint are covered with a smooth slippery covering called hyaline cartilage. There is a thick burlap-like material that encases the entire joint called the capsule. This capsule is lined by a thin layer of cells called the synovium that produces the thin “oil” that lubricates the joint.
When the joint surfaces start to erode, as in degenerative arthritis, bone spurs start to form at the edges of the joint. Occasionally, the capsule encasing the joint will tear and the synovial lining will “pop out” of this tear. The synovial cells don’t know any better and therefore continue to produce synovial fluid. A cyst forms and will continue to grow. If the cyst grows in a region that has no sensitive structures, such as the wrist, there will be no symptoms. If however, the cyst grows in an area that will cause compression to structures that can’t take compression, symptoms will result.
It just so happens that the facets in the back of the spine are diarthrodial joints and exhibit degenerative changes quite commonly. The condition “degenerative spondylolysthesis” is one of the most common spinal disorders and is a result of wear and tear on the facet joints. (See the section on degenerative spondylolysthesis for further information on this condition). In a small number of patients with this condition, ganglion cysts in the lumbar spine will form.