SPINE - SPINE INSTABILITY

Treatment Options:

Spinal Fusion

The traditional treatment for pain caused by instability or disc degeneration is spinal fusion.  This is a surgical procedure in which the disc tissue is removed and bone is placed between the vertebrae (the bones of the spine).  The goal of this surgery is to fuse the vertebrae around the disc that is causing pain.

Sometimes, metal plates, screws, or rods are used to stabilize the spine while a fusion occurs.  The metal is not the fusion.  It only provides temporary stability while a bone fusion develops.  The metal supports remains in place unless they become a problem for the patient.  The critical portion of a fusion procedure is the surgical technique used to prepare the bone surfaces.   All fusion operations require the growth of bone in order to be successful.  Bone can be obtained from the patient (autograft), or from a bone bank (allograft / cadaveric bone).  Newer manufactured proteins (BMP) are available to stimulate the growth of bone.

There are two ways that individual patients can improve the results of their fusion operation.  First, patients who smoke should reduce or quit smoking prior to surgery. Smoking has been shown to reduce the likelihood of achieving a solid fusion.   Smoking also contributes to numerous other complications associated with surgery.  Secondly, patients should wear any supportive braces or collars that are recommended by the surgeon. Braces limit the amount of motion in the spine, improving the likelihood of a solid fusion.

Artificial Discs

What is an "artificial disc?"

The "disc" in your spine is the soft cushioning structure located between the individual bones of the spine, which are called "vertebrae."  The disc itself is made of cartilage-like tissue and consists of an outer portion, called the annulus, and an inner portion, called the nucleus.  (An analogy often given is a jelly doughnut, where the doughnut is the annulus and the jelly inside is the nucleus.)  In most cases, the disc is flexible enough to allow the spine to bend comfortably.  When it is not, it can cause a great deal of pain. 

An artificial disc (also called a "disc replacement," "disc prosthesis," or "spine arthroplasty device") is a device that is implanted into the spine to imitate the functions of a normal disc, which are to carry load and allow motion. 

Artificial discs are usually made of metal or plastic-like (biopolymer) materials, or a combination of the two.  These materials have been used in the body for many years.  Disc replacements have been used in Europe since the late 1980s.  The most commonly-used disc replacement designs have two plates.  One plate attaches to the vertebra above the disc being replaced and the other plate attaches to the vertebra below.  Some devices have a soft, compressible plastic-like piece between these two plates.  The devices let the spine move by use of smooth, usually curved, surfaces sliding across each other.  They are designed to allow motion after surgery that is as normal as possible.

Who needs an artificial disc?

The most significant indication for disc replacement is pain arising from a degenerated disc.  If that pain is not adequately reduced by non-operative care (medications, injections, and/or physical therapy), a disc replacment may be appropriate.

Usually, you will have had an MRI showing disc degeneration.  Sometimes a discogram is performed to verify which disc(s), if any, is related to your pain.  (A discogram is a procedure in which dye is injected into the disc and X-rays and a CT scan are taken.)  The surgeon will compare the results of the discogram and your MRI with your description of your symptoms and your physical examination to help determine the source of your pain.

Advantages of an artificial disc

With fusion, there is a possibility that the fusion of one part of the spine may force the discs and vertebrae above and/or below the fused portion to bear more load and motion.  This may result in more wear and tear than in normal.  The artificial disc may reduce this risk.

Another possible advantage of disc replacement is a faster return to activities than after a fusion surgery.  Patients who have fusions have limited activities during the time required for the bone graft to grow into a solid mass.  Since one of the goals of artificial discs is maintaining range of motion, patients are encouraged to gradually return to activities earlier.

Several conditions may prevent you from receiving a disc replacement.  Primarily, they are spondylolisthesis (the slipping of one vertebral body across a lower one), osteoporosis, vertebral body fracture, allergy to the materials in the device, spinal tumor, spinal infection, morbid obesity, significant changes of the joints in the back portion of the spine (called "facet joints"), pregnancy, chronic steroid use, and autoimmune problems.

Which surgery is for you

Although artificial discs offer several advantages over fusions, this is a relatively new technology with no long-term randomized, controlled clinical study results.  Fusion has a long-standing record of success in permanently correcting problems in the fused motion segment of the spine.  Discuss both options thoroughly with your neurosurgeon before deciding which procedure is best for you.

 Contact our New Patient Coordinator at 404-256-2633 to arrange for evaluation of your spinal instability or discussion of artificial discs.