What causes a vertebra to slip backward?

Q. What is retrolisthesis?

A. Retrolisthesis means that one of the spinal bones (vertebrae) has moved backwards beneath the spinal bone above it. Imagine a stack of rectangles arranged neatly one on top of the other. If you are looking at this stack from the side, a rectangle pushed backwards relative to the rectangle above it is a bit like what is happening in the spine with retrolisthesis. The word comes from the combination of "retro" (meaning backwards or behind) and "listhesis," meaning to slip or slide.

X-rays of the spine may show retrolisthesis even in people who feel fine. On the other hand, slippage of a vertebra may cause pressure on a nerve or the spinal cord. Causes of retrolisthesis include:

• fracture of the spine or ligament damage due to an injury
• age-related deterioration of the discs between the vertebrae
• damage or degeneration of joints and/or ligaments of the spine
• osteoporosis, nutritional deficiencies, or other causes of weakened bones
• congenital defects that cause abnormal spinal alignment that is present at birth.

Treatment of retrolisthesis depends on its severity and the presence or absence of symptoms. For example, if retrolisthesis is discovered after x-rays are performed but no relevant symptoms are present, no treatment may be necessary.

When symptoms are present, your doctor may initially recommend exercises, physical therapy, and/or a brace. Pain relievers (such as acetaminophen), anti-inflammatory medicines (such as ibuprofen), muscle relaxants, and/or an injection of a corticosteroid may be recommended. Surgery is usually a last resort for significant symptoms that are not improving enough with other treatments; the goal is to re-establish normal alignment and stability. For fractures associated with retrolisthesis, a brace or surgery (or both) may be recommended.

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