A spondylolisthesis occurs when one of the bones in your spine – called a vertebra – slips forward and out of place. It can occur anywhere along the spine but is most common in the lower back (lumbar spine). In some patients, this causes no symptoms at all while others may have back, leg, or thigh pain that ranges from mild to severe. There are multiple types of spondylolisthesis.
Degenerative spondylolisthesis occurs after wear and tear and arthritic changes occur in the intervertebral discs, leading them to dry out and weaken. As arthritis develops it also weakens the joints and ligaments that hold the vertebrae in the proper position. Once these structures become incompetent, a vertebrae can slip forward over the vertebra below it. This slippage can narrow the spinal canal as well as the channels where the nerves exit to the legs and cause pressure on them. This narrowing is called spinal stenosis and is a common problem in patients with spondylolisthesis.
The spondylolitic type occurs when the area of bone that connects the front to the back of a vertebra – called the pars – breaks or separates from fatigue. This can lead to a lack of structural support of the front part of the vertebra causing it to slip forward.
Watch the video below to learn more about spondylolisthesis.