Lumbar spine fusion for degenerative disc disease

By: Paul C. McAfee, MD
May 30, 2006

Spinal fusion surgery

A lumbar spine fusion is a type of back surgery designed to treat low back pain from degenerative disc disease. It is called a “spine fusion” because the surgery involves placing small morsels of bone either in the front of the spine (in the disc space) and/or along the back of the spine (in the posterolateral gutter) so that the bone grows together and fuses that section of the spine. The fusion is designed to eliminate motion in that fused segment of the spine, thereby decreasing or eliminating the back pain created by the motion. The spine is not actually fused at the time of the surgery. Instead, the surgery creates the conditions for the spine to be able to fuse and the fusion is a process that will set up over a 3 to 6 month (and up to 18 month) period of time following the spinal fusion surgery (see figure 1).

Lumbar spinal fusion surgery for low back pain caused by degenerative disc disease is usually considered an option for patients who:

• Have not found sufficient pain relief from extensive—usually at least six months—of non-surgical treatment (such as physical therapy, medications, and other treatments)

• Have ongoing low back pain that limits their ability to function in their daily activities at work and/or at home

• Have received a diagnosis that a specific disc space is the pain generator and other possible causes of the patient’s low back pain have been considered and ruled out

It is important to stress that the decision to undergo a fusion procedure for low back pain is entirely the patient’s decision and he or she needs to carefully weigh the risks and possible complications along with the potential benefits of surgery, as well as consider the full range of alternatives to a spine fusion surgery. It is often a good idea for patients to get a second (or third) opinion from other surgeons and/or other types of spine specialists prior to deciding whether or not to have spinal fusion.

The decision to have a spine fusion procedure to treat low back pain from degenerative disc disease is a very personal one. Degenerative disc disease is for the most part a non-crippling, non-progressive type of back condition, although in a minority of cases it can be cause severe back pain and can significantly impact on an individual’s ability to function.

Historical perspective on spine fusion surgery

Fusion surgery for the treatment of lower back pain has been done since the early 1900’s. At that time, spine fusion procedures were done to limit the deformity created by tuberculosis infections, and it was found that not only did the fusion procedure limit the deformity, it also reduced the patient’s low back pain as well.

Since then, spine fusion procedures have had variable popularity for the treatment of pain from lumbar degenerative disc disease and remain somewhat controversial in the medical community. Surgeons and researchers span the spectrum in terms of their beliefs as to how useful spine fusion surgery is and when and how it should be performed.

• Some spine surgeons do not believe fusion surgery is at all useful and is never indicated for the treatment of low back pain from lumbar degenerative disc disease.

• Some spine surgeons are very willing to offer patients a fusion procedure, and some are even willing to do multiple level fusion surgery.

As with most things in medicine, the truth lies somewhere in between the two far ends of the spectrum of beliefs about spine fusion surgery as a treatment for low back pain from degenerative disc disease. In general, when done by a skilled surgeon for a patient with the right indications, spinal fusion surgery is usually an effective treatment that brings significant relief from severe, ongoing low back pain caused by degenerative disc disease.

Each patient has to weigh the risks of a major surgical procedure and a long healing process with the potential benefits. The spine fusion surgery works best for treating one level of the spine, although two levels can be fused if the patient has severe low back pain. As the number of levels fused increases, the risks of the procedure increase (e.g. a nonunion) and the potential benefits decrease. Only rarely and in extreme cases would most spine surgeons recommend or even offer a three or four-level spine fusion surgery.

Two of the most important factors that impact on whether or not a fusion procedure will be successful in reducing low back pain include:

1. Indications for spinal fusion

2. Obtaining a solid spine fusion