Lumbar Herniated Disc

General description

Discs are the relatively soft, gelatinous cushions (nucleus pulposis) surrounded by a thick fibrous cover (annulus fibrosis). The disc functions as a shock absorber between the hard, bony vertebrae. A herniated disc is a protrusion of the nucleus through the annulus which in turn presses against a nerve traveling through the spinal canal.

Discs herniate most commonly in the lower back, although they also occur frequently in the lower neck and more uncommonly may occur anywhere.

Patient's often ask what the disc looks like. Below is a picture of a 6mm lumbar herniated disc. The consistancy of the disc is like crab meat.

Causes

A disc may herniate because of sudden trauma, anything from a fall on an icy sidewalk to an athletic injury or by simply lifting the wrong bag of groceries in the wrong way at the wrong time. Disc Herniations may also be caused simply by the cumulative long term effects of what doctors like to call poor body mechanics - a lifetime of too much bending and twisting and too many awkward positions. Herniations in the lumbar and cervical spine occur with increased frequency in middle aged patients (30-50 years old). This is because the relatively flexibility and regenerative ability of youth is slowly replaced with the stiffness and disc degeneration of progressive age.

Signs and symptoms

Depending on where the herniation occurs, and the degree to which nerves entering the spine, or the spine itself, are affected, a wide range of symptoms are possible. In addition to pain around the site of the herniation, many disc patients also experience significant pain somewhere other than where the disc is. This is because when discs ooze and bulge, they ooze and bulge into spaces occupied by nerves. Because these nerves are carrying impulses from different parts of he body to the spine and then to the brain, the pain is experienced as if it were occurring in the area from where the nerve originates.

With lower back herniations caused by trauma, patients typically experience sudden and severe pain which usually recedes without treatment and then gradually worsens over time. Often , if the sciatic nerve, which carries impulses from the legs to the spine, is involved there is dull, burning pain in the back of the leg, sometimes extending all the way to the foot. Sitting, bending, sneezing, coughing - almost anything that can cause the disc to exert pressure on the nerve, will cause pain.

Diagnosis

In herniations of discs in the neck, pain may appear in the shoulder, neck, outer part of he upper arm, or the inside of the forearm.

Physical examination can often reveal not only the fact of a herniation but even its site. For example, a herniation between the fourth and fifth lumbar vertebrae will manifest itself by a patient having difficulty bending the big toe and in attempting to walk on the heels. (Of course, everybody, except perhaps circus acrobats, has trouble walking on his heels, but, not to worry, years of training and experience have uniquely qualified your doctor, to distinguish between a natural healthy clumsiness and the signs of a diseased disc.)

Similarly, herniations in the neck often reveal sensory deficits and weaknesses in the muscles of the arms, the thumb and some of the fingers, depending o the location of the affected disc. Several kinds of imaging tests, including x-rays, CT scans, MRI's and other more exotic imaging tests can confirm and elucidate the findings of a physical exam. In general, bulging discs are rarely a diagnostic mystery.

Treatment

Treatment is a different story. To be honest, doctors often disagree about the treatment of disc disease. The fact is, there are many different kinds of treatments available;and just as different doctors often approach the same problem in different ways, different patients sometimes respond to the same treatment in very different ways.

Most doctors at least agree that initially, conservative treatment is best, unless there is clear evidence of severe nerve involvement, significant loss of sensation, partial paralysis, or bowel or bladder dysfunction. Conservative therapy includes such things as bed rest, mild stretching exercises, heat or ice, massage, braces or corsets, and drugs to reduce pain, relax muscles and reduce inflammation. Cervical (neck) or pelvic (lower back) traction, ultrasound therapy and electronic nerve stimulation are also options.

When conservative therapy fails

For discs that do not respond to conservative treatment, there is a surgical option. Actually, the truth is there is more than one surgical option, and this is where most of the controversy in the treatment of disc disease originates.

Basically, surgery cannot repair the disc itself. What surgery can do is provide more room for the herniated disc to bulge in, thereby reducing pressure on the nerves and therefore pain.

New clinical studies indicate there are some advantages to choosing surgery over non-invasive treatment for certain conditions.

In the New England Journal of Medicine: Surgery versus Prolonged Conservative Treatment for Sciatica: View the abstract of the study.

In JAMA 2006: A study of surgical vs non operative treatment for lumbar disk herniation. Read the article here.

Laminectomy vs. Laminotomy

The older, more radical version of this surgery is called a laminectomy. The lamina, or back of the spinal canal is entirely removed.

In the newer version of this procedure, called a laminotomy, only the small part of the lamina directly surrounding the affected disc is removed.

Although some doctors still prefer the older more radical surgery, there is growing evidence that the newer, less invasive procedure, the laminotomy is superior. The reason is simple: the more bone that is removed, the less strong and stabile the remaining structure is. While removing more lamina will often relieve symptoms initially, there is far greater rate of subsequent complications, often worse than the original problem, because of the resulting spinal instability.

In virtually all cases, we strongly recommend laminotomy over laminectomy.