What Should I Know About Lumbar Spinal Fusion?

In select circumstances in which these treatments fail, a physician may discuss with you that your best long-term outcome could be achieved with a lumbar fusion. There are several important aspects of lumbar fusion surgery to understand.

•In what circumstances might a fusion be recommended?
•How does a fusion actually improve your pain?
•How does a surgeon perform a lumbar fusion?

Causes of Back and Leg Pain
In order to first understand why a fusion may work, one must understand the possible mechanisms for back and leg pain. A physician may recommend a lumbar fusion in circumstances where the predominant source of back pain is thought to be a severely degenerated disc between two vertebral bones or to a "slippage" of the spine bones (which is referred to as "spondylolisthesis"). Slippage of the bones results in misalignment of the spine and possible entrapment of the spinal nerves. Other circumstances exist in which a fusion may best treat the source of back and leg pain. When referring to what discs are involved, a physician will refer in medical jargon to the "levels involved." A one-level fusion links or fuses together two vertebral bones on either side of a diseased disc. A two-level fusion links or fuses together three vertebral bones with two intervening discs. A fusion is an actual bridge of solid bone that is created by surgery and links the bones together to maintain alignment and provide stability and strength. It is believed that pain originates in levels of the spine where the bones are slipped or the discs or joints are damaged and produce pain. This may be due to irritated nerve endings around the disc, bone or joints themselves or due to actual entrapment of the spinal nerves in that region. By eliminating motion across the damaged level, pain can be improved. A solid bridge of bone eliminates motion that normally would take place at the disc space and in the joints of the spine.

A lumbar fusion may be recommended for diagnoses such as a recurrent disc herniation, lumbar spondylolisthesis, scoliosis or curvature of the spine, severe disc degeneration, or for a traumatic injury of the spine such as a fracture. All of these different conditions can cause back and leg pain.

Aspects of the Surgical Procedure
A lumbar fusion can be achieved in a variety of ways and through several different approaches to the spine. What that means to you the patient is that an incision may be made on your abdominal wall, your flank, your backside, or a combination of these approaches. "Anterior" means "from the front" and "posterior" means from your backside. A surgeon will study your x-ray studies and determine whether you will require one approach or the other (or, in less common circumstances, both). Though you may know many people who have had a fusion, keep in mind that many options are possible and your surgeon will select the approach and technique that is best tailored for your spine.

He/she will also decide whether titanium metal screws would be beneficial. These are typically placed through the "pedicle" bone of the spine and thereby allow purchase of the back, middle and front parts of your vertebral bones. These screws are attached to a rod or plate that is contoured to your spine. This type of spinal "instrumentation" provides immediate strength to your spine during the process of bone fusion.

In other situations, a titanium metal "cage" or bone cylinder may be screwed into your disc space. This is called an interbody fusion because it is between the "bodies" of the vertebral bones and is across the diseased disc space. This can be done from the front (anterior) or from the backside (posterior). An approach through the abdomen (anterior) may be done "laparoscopically" with several small incisions or "open" through a single incision. Your surgeon can discuss the advantages and disadvantages of both techniques as well as what has worked best in their own surgical experience. Typically, these bone or metal "cages" or cylinders are packed with bone graft taken from either your pelvis (ileum) or tailbone (spinous processes and laminar bone). Bone graft serves as the source of bone cells to help initiate the fusion process at the surgery site. In some circumstances, cages may be used in conjunction with pedicle screws. Other techniques involve placement of bone marrow or "graft" along the sides of your spine (with or without screws). This is called a "posterolateral" lumbar fusion and is another effective way to fuse a level of the lumbar spine. The source of the bone graft material in your pelvis (ileum) can remain painful for weeks or months following surgery but gets better in the majority of patients.

Surgery: Risks and Recovery
The risks of lumbar fusion surgery are similar to other spine operations and should be discussed at length with your surgeon.

Following surgery, you may be asked to wear a plastic brace or cloth corset for a period of time (weeks or months). Some surgeons do not use braces at all, and what your surgeon recommends will likely be based on what they have found to be most successful in their own practice.

The process of healing a fusion can take many months or well over a year to be complete. For these reasons, it is important to realize before surgery that positive results will be slow to realize and patience following your surgery will be necessary. A fusion is not a quick fix; rather, it is a commitment of patient and surgeon to a long process of improving your back and leg pain. Total or 100% cures are rare. Realistically, patients can expect a dramatic and lasting improvement in their back and leg pain. Though many patients are worried about a lumbar fusion taking away their ability to bend and twist, the majority of patients eventually regain the ability to bend in all directions. This mobility can allow for a return to work and many enjoyable recreational activities. The success rates of lumbar fusion can be lower in patients who smoke, are overweight, have diabetes or other significant medical illnesses, have osteoporosis, or who have had radiation treatments that included the lower back. Good nutrition and slowly increasing activity (as recommended by your physician) in the recovery period can help achieve success.

In the future lumbar disc or joint replacement may be an answer to the debilitating back and leg pain associated with lumbar spinal problems. Current surgical techniques allow for a variety of approaches to the lumbar spine and an increasingly safe and effective means of achieving bone fusion. The goal: improve your back and leg pain.

Recommended Exercise
The benefit of exercise for your low back depends on three key principles. First, you must attain satisfactory aerobic fitness. Second, you should focus part of your work-out on the muscle groups that support your back. Third, you must avoid exercises that place excessive stresses on your back.

The ideal aerobic exercise involves the large muscle groups of your body (arms and legs) in a smooth, cyclical fashion. Recommended exercises include swimming, fast walking, cycling, and using a ski machine or elliptical exerciser. You should achieve the appropriate heart rate for 30 minutes at least three times per week. Of course, you should consult your family physician and review your aerobic program before getting started. He/she can give you the appropriate target for your heart rate during aerobic exercise. It is always optimal to approach your aerobic goals slowly, especially if you have not recently worked-out. Part of your work-out should stretch and strengthen the muscles of your low back, abdomen, pelvis and thighs. Flexibility in these areas will greatly decrease the chance of further injury to the back. By strengthening these muscle groups, the body's weight distribution and posture are improved, resulting in less stress on the low back. It is best to perform these exercises after a good "warm-up", such as your aerobic routine. Ask your health club staff or physical therapist for instructions on specific stretching and strengthening exercises for these areas.

While the merits of good conditioning cannot be overstated, the wrong type of exercise may actually worsen your low back problem. Activities that impart excessive stress on the back such, as lifting heavy weights, squatting, and climbing are not advised. In addition, high impact exercises such as running, jumping, and step aerobics can aggravate a low back condition. When walking, wear well-cushioned shoes with good arch supports and use a treadmill or a track made for athletics. Cycling on a recumbent stationary bike can relieve stress on the back.

With the help of your physician, physical therapist and health club staff, you can achieve proper physical fitness. Your low back pain may be decreased and your lifespan increased!