Lumbar Spinal Stenosis

Stenosis simply means, a constriction or narrowing of a duct or passage; a stricture. In the case of the spine, the narrowing always refers to the passage way of the nerves or spinal cord. This passage way is either the openings for the nerves or the spinal canal itself.

The spine is made up of stacked bones, like spools of thread, called the vertebrae. Between the bones are the soft flexible discs, which allow us to bend and turn.

As we age our tissues begins to dehydrate (lose water). This process causes our discs to dry out thus decreasing the area of cushioning between each vertebra. Normally our discs separate each vertebra, act as shock absorbers during regular activity, and allow our spine to move freely. A decrease in the area of cushioning leads to trauma of our vertebrae and formation of osteophytes (spurs). This condition is referred to as Spondylosis.

Spinal stenosis usually occurs in older people after years of wear and tear, or degeneration of the spine. This wear and tear results in changes in the structures around the spinal canal. These changes include thickening of the large ligaments that connect the vertebra together, bone spurs around the facet joints and disc space, and bulging of the discs themselves. All of these changes push into the spinal canal, making the tube of the spinal canal smaller. Eventually, there is not enough space in the spinal canal for the nerve to fit comfortably without causing injury to it. Stenosis can also develop from injuries, infections, or tumors. Some people even have a narrow spinal canal from birth, an abnormality that leads to symptoms of Stenosis early on life.

Normal	Early Stenosis	Severe Stenosis

The narrowing of the spinal canal can lead to irritation of the nerves of the spine. This can cause pain and problems with the proper functioning of the nerves. The lack of space can also cause the supply of blood and oxygen to the nerves to be reduced. When the nerves need more blood flow during increased activity, the blood vessels may not be able to swell to get more blood to them. This can lead to numbness and pain in the nerves that are affected. In addition, the nerves lose some of their mobility when the space available to them is reduced. This leads to irritation and inflammation of the nerves. Stenosis can occur in all areas of the spine, but it is most common in the lumbar spine.

When this happens, there can be a significant amount of pain, numbness, and/or weakness in the buttocks, thighs, and legs. Often, this can severely limit or altogether stop the patient from walking. The discomfort usually disappears after 5 -10 minutes of rest. Lying with the legs flexed, sitting, or squatting can also help as these maneuvers increase the area of the spinal canal. These symptoms may begin in the lower legs and progress upwards toward the buttocks or they may begin in the buttocks and progress downward. Low back pain is also a very common complaint. The symptoms may begin on one side but will often end up involving both sides. You may hear your doctor refer to this as neurogenic claudication.

LSS can also cause pain extending down the leg along the area that corresponds to the affected nerve root. This occurs because the area where the nerve root exits the spinal canal (foramen) has become narrowed causing pressure on the nerve root.

The operations typically used to treat Lumbar Stenosis include the classic laminectomy, laminotomy, and foraminotomy. For patients who meet the proper indications, these procedures can also be combined with a spinal fusion operation, when necessary. The most commonly used decompressive surgery is the laminectomy. To perform a classic laminectomy a 3-4 inch incision is made in your lower back, though it may be longer depending on how many levels of your lamina are affected.

Lumbar Laminectomy