Segmented Instability of the Spine

Segmented Instability of the Spine

Each spinal segment is like a well-tuned part of a machine. All of the parts should work together to allow weight bearing, movement, and support. A spinal segment is composed of two vertebrae attached together by ligaments, with a soft disc separating them. The facet joints fit between the two vertebrae, allowing for movement, and the foramen between the vertebrae allows space for the nerve roots to travel freely from the spinal cord to the body. When all the parts are functioning properly, the spinal segments join to make up a remarkably strong structure called the spine. When one segment deteriorates to the point of instability, it can lead to localized pain and difficulties.

Segmental instability occurs when there is too much movement between two vertebrae. The excess movement of the vertebrae can cause pinching or irritation of nerve roots. It can also cause too much pressure on the facet joints, leading to inflammation of facet joints. It also may cause muscle spasms as the paraspinal muscles try to stop the spinal segment from moving too much. The instability eventually results in faster degeneration of the spine in this area.

It is hard to determine which problem comes first in segmental instability. In some cases, degeneration of the disc begins the process. Once the disc is no longer able to function normally, the degeneration process of ALL parts of the spinal segment begins. As the disc continues to degenerate, the facet joints become arthritic, bone spurs form around the joints, and the segmental instability gets worse. This cycle continues.

Diagnosis

Before a health care professional can diagnose your condition and design a treatment plan, a complete history and physical examination are necessary. There are so many possible internal causes of pain; it is important to determine what is and is not causing the problem. After the physician has a better idea of what is attributing to your discomfort, diagnostic tests of some sort may be recommended.