Spondylolisthesis: What is It?

Health Professional

Spondylolisthesis (spaun-di-lo-lie-thee-sis) is a mouthful and is a common cause of low back pain (although it can exist anywhere in the spine, the lumbar spine is the most common area affected). The spinal column is a series of building blocks called vertebral bodies stacked on top of one another. Sometimes these blocks do not line up perfectly. This slight separation in the spinal column is called a spondylolisthesis.

"Doc says I have a spondy-something-or-other. Don't ask me what it is; all I know is that it hurts". Steve tries to explain his low back condition to his friend. But, he finds that he cannot explain what he does not understand.  Steve has had back pain for a number of years. Every year the pain gets worse and has now become constant. His doctor sent him for x-rays recently. The x-rays showed a spondylolisthesis with disc degeneration at L5/S1. Steve could not understand his doctor's explanation of the condition. So, now he has pain and has confusion.

With a word like "spondylolisthesis", it is easy to understand the confusion. Now is the time to create a better understanding with an analogy. Imagine a flagpole that is broken in half. The two pieces could stay together if the flag's rope is very tight. However, once the wind blows and the ropes loosen, the two pieces of the pole can separate. The flag-pole represents the spine which has many pieces put together. The rope represents the ligaments that bind the pieces together. And the wind is the sheer forces and gravitational forces that try to pull everything apart. Once the pieces of the spine separate, a person has the condition called a spondylolisthesis. Sometimes it is useful to think of it as "vertical instability" because the vertical alignment is not held stably together.

Once Steve is able to understand the concept of spinal instability and spondylolisthesis, he wants to know why he has it. What did he do to deserve this constant back pain? Sure, he is a little obese and he took some bad falls in his younger days. But, how can any of that amount to sheer, utter misery?

Spondylolisthesis comes in three main varieties: spondylolytic, degenerative, and developmental. Spondylolytic spondylolisthesis is a separation which is primarily caused by a break in the bones of the spine. This bone problem could resulted from a traumatic fracture, abnormal wear, or a birth defect. Gymnasts and football players are particularly susceptible to a traumatic spondylolytic spondylolisthesis. Degenerative spondylolisthesis is a separation which is primarily caused by loosening of the ligaments as the spinal disc shrinks and degenerates. The spinal ligaments are a fixed length that spans the space occupied by the spinal disc, like a bridge. As the disc shrinks, the ligaments lose their natural tightness because the gap narrows and brings the ends of the ligaments closer together. This slack in the line creates instability and separation. As people age, degenerative spondylolisthesis becomes more likely. Another spondylolisthesis variety is developmental spondylolisthesis. This condition initially presents in children and adolescents. These young people with spondylolisthesis were born with an abnormally shaped spinal column, or pelvis, or tailbone, or any combination of the three. Spondylolytic, degenerative, or developmental; all of the varieties of spondylolisthesis result in essentially the same problem: a separation of the spinal segments and a pain in the back.

Whether called spinal instability or spondylolisthesis, either way this common cause of low back pain is usually at its worst in positions that emphasize the arch of the low back. Bending backwards, walking, and standing; all of these activities provoke the pain from a separated, unstable spinal segment. However, pain is not the worst outcome from an unstable spine. The worst case scenario for spondylolisthesis is ongoing, progressive damage to the spinal nerves or even the spinal cord. This nerve damage can manifest as weakness, incontinence, or numbness. The amount of problems caused by spondylolisthesis is directly related to the amount of separation between the spinal building blocks. The amount of separation and resulting nerve damage is usually what determines the type of treatment. When the spine does not line up perfectly, extra care needs to be taken to prevent a lifetime of problems. Spondylolisthesis is something someone is born with or acquires during his/her life. No matter how it happened, many people play the cards they are dealt and live happy, active lives with a "spondy".