Retrolisthesis: A Simple Explanation
Retrolisthesis is when one of the bones in your spine (a vertebra) slips backward relative to the bone below it—imagine a stack of coins where one coin slides slightly toward the back of the stack. 1
How It Happens
- Your spine is made up of individual bones (vertebrae) stacked on top of each other, and retrolisthesis occurs when one vertebra moves backward out of its normal alignment with the vertebra beneath it 1
- This backward slippage is the opposite of the more common forward slippage (anterolisthesis or spondylolisthesis), where a vertebra slides forward instead 2
- The condition typically develops due to wear-and-tear changes in the spine, including disc degeneration (when the cushions between vertebrae break down) and arthritis of the small joints in the back of the spine 3, 4
Where It Occurs
- Retrolisthesis most commonly affects the upper and middle parts of the lower back, particularly at the L2, L3, or L4 levels 3, 2
- It can also occur in the neck (cervical spine), though this is less common 1
- The condition is found in approximately 17-23% of people with spine problems, making it relatively uncommon compared to forward slippage 4, 5
What Causes It
- Disc degeneration: When the cushioning discs between vertebrae wear out, they lose height and the spine becomes less stable, allowing backward slippage 3, 4
- Facet joint arthritis: Arthritis in the small joints at the back of the spine contributes to instability that permits backward movement 3
- Spinal alignment issues: People with certain spine shapes—particularly those with increased forward curvature in the upper-to-mid back region—are more prone to developing retrolisthesis in the lower back 3, 2
- Age-related changes: The condition becomes more common with increasing age as the spine undergoes natural degenerative changes 4, 5
Grading Severity
- Doctors measure retrolisthesis as a percentage of how far back the vertebra has slipped, with Grade I (the mildest form) representing backward movement of less than 25% of the vertebra's width 4, 5
- Most people with retrolisthesis have Grade I slippage, which is considered mild 5
Clinical Significance
- Interestingly, retrolisthesis by itself may not always cause significant pain or disability—many people have it without knowing 4
- When retrolisthesis occurs alongside other spine problems (like a herniated disc), the symptoms are often primarily due to those other conditions rather than the retrolisthesis itself 4
- In some cases, retrolisthesis may actually represent the body's attempt to compensate for other spinal alignment problems, particularly in people who also have forward slippage at a different level 2
- The backward slippage can potentially narrow the spaces where nerves exit the spine (foraminal stenosis), though this doesn't always cause symptoms 6, 4