Spinal Stenosis

Introduction to Spinal Stenosis

The spine is composed of 33 vertebrae, uniquely aligned to support the body and provide a passageway for the spinal cord and nerves.

The vertebrae and connecting intervertebral (between the vertebrae) discs are stacked upon each other in such a way as to provide a clear, open channel for the spinal cord. As part of the central nervous system, the spinal cord connects the nerves of the body to the brain.

What is spinal stenosis?

Stenosis refers to a narrowing of an opening that is normally larger. In spinal stenosis, the normally clear, open channel in the spine has become narrow, resulting in too small of a pathway for the spinal cord.

What causes spinal stenosis?

Genetic or congenital problems can influence the development of spinal stenosis. More frequently, self-destructive activities contribute to stenosis, such as poor posture and body mechanics, obesity, physical abuse, smoking and inadequate diet. In addition, other spinal diseases such as osteo- and rheumatoid arthritis, scoliosis, osteoporosis and lordosis (sway back) can result in spinal stenosis.

Can spinal stenosis be prevented?

Addressing the causes is the key to prevention. Although genetics and congenital problems usually are not controllable, preventing spinal disease is, even for those with a genetic tendency towards stenosis. Lifelong practices of good spinal and joint health can help reduce the chance for spinal stenosis. Dr. Leary's private practice offers preventative advice and helpful exercises designed to strengthen the spine.

What treatment options exist for spinal stensois?

1. Foraminotomy

The foramen is the natural passage or tunnel between the vertebrae of the spine through which a nerve root exits from the spinal canal on its path to a specific tissue or organ. When this foramen becomes narrowed, the nerve can become irritated or dysfunctional.

Removing bone and soft tissues to enlarge the passage for the nerve is called a foraminotomy. A foraminotomy is commonly performed as part of a decompression of the spinal canal itself. In some cases a foraminotomy may be performed from outside the canal and not involve any direct decompression of the central canal if the pressure is strictly on the nerve root. To perform this operation, specialized instruments are used to remove portions of bone from the laminae, facets and facet capsules.

2. Surgical decompression

This refers to any surgical technique which aims to free the space for the nerves in the spinal canal or foramena. A spinal decompression for stenosis can be performed in the cervical spine (neck), the thoracic spine, and in the lumbar spine. A decompression involves removing tissue which is constricting or compressing nerve structures. In some cases the spine becomes unstable and a spinal fusion is performed at the time of surgery.

A number of different surgical methods are commonly used to achieve a decompression, including: laminectomy, laminotomy, laminoplasty, foramenotomy, anterior discectomy. The ideal technique to use will depend largely upon the level of the spine that must be decompressed, the elements which are causing the compression (bone, disc, ligaments or other), the stability of the spine, and the surgeon's experience. Dr. Scott Leary is renowned as a physician who combines leading edge clinical practice with compassionate care to deliver the best patient outcomes.

3. Laminectomy

In the laminectomy procedure, the spine is approached through a two-inch to five-inch incision in the midline of the back, and the left and right back muscles are detached from the lamina on both sides. The lamina is removed (laminectomy), which allows the doctor to see the nerve roots. The facet joints, which are directly over the nerve roots, may then be trimmed to give the nerve roots more room.

4. Laminoplasty

When the spinal canal becomes narrowed and the spinal cord and nerves are compressed, surgery may become necessary. One type of surgical procedure is called a laminoplasty, which refers to opening up the space of the spinal canal by splitting the laminae. The laminae, which, in simple terms are like a set of double doors over the spinal canal, are "swung open". First the spinous process (the "bump" you feel at the back of the spine) is removed. Then the central portion of the laminae is split and each lamina (right and left) is hinged open. The hinged laminae are kept open through bone struts, sutures, or other techniques. A laminoplasty can lead to marked enlargement of the space available for nerves and the spinal cord.

5. Laminotomy

When the spinal canal becomes narrowed or the nerves compressed, a laminotomy can be performed to free up the space of the spinal canal by removing a portion of the lamina. The procedure involves making an incision into the layer of muscles and ligaments that sits on either side of the spine, and freeing up the attachments to the spinous process and lamina to expose the laminae to full view. Using a special instrument that removes little bites of bone, the lamina is gradually trimmed until sufficient bone is removed to free the compressed nerve This "unroofs" a portion of the spinal canal and resulting in enlargement of the space available for the nerves.