Surgery for Spondylolisthesis
Spine surgery for spondylolisthesis is a much-debated topic. While most surgeons agree that decompression of the nerves may benefit the patient, the question is whether the slipped vertebra needs to be realigned at all. It depends on what caused the spondylolisthesis.
Traumatic spondylolisthesis (type II C or type IV—see the article Causes of Spondylolisthesis for a full description of the types of spondylolisthesis) can generally be easily realigned with surgery. The spine hasn't yet readjusted to accommodate the slip, so not as many spinal structures have been compromised (that's doctor speak—not as many parts of your spine have been affected or had to readjust how they're working to make up for the slipped vertebra). To help restore your spinal alignment, your doctor may recommend surgery.
However, for other types of spondylolisthesis, spine surgery is seldom the first treatment, and this is where the debate comes in. Type I spondylolisthesis, for example, is congenital, meaning it's present at birth. The rest of the spine has usually readjusted to work around the deformity, so fixing the spondylolisthesis may actually lead to other problems.
This is also the case with type III spondylolisthesis, which is caused by the gradual process of degeneration. Decompression (taking pressure off the nerves) and fusion may be needed, but reducing (or realigning) the slippage is the area of concern. For patients with a more long-term spondylolisthesis, suddenly restoring alignment with spinal hardware may lead to bone fractures, increase the possibility of nerve injury, and increase the risk of hardware failure (you can find more details on spinal hardware further on in this article).
In most cases of spondylolisthesis, non-surgical treatments are tried for several months. If non-surgical treatments do not relieve your pain, your doctor may recommend surgery. It's completely acceptable at this point for you to request a second opinion. Surgery is a very serious decision to make, so you should feel as informed as possible.
Your spine surgeon will decide which procedure is best for you and how the surgery will be performed. Ask as many questions as you want about the procedure: what will happen before, during, and after the surgery; how long the recovery will take; what instruments the surgeon will use. You should know as much as you can about the surgery before heading to the operating room—that's part of being an informed patient.
Types of Surgery for Spondylolisthesis
There are 3 typical surgical procedures for spondylolisthesis: ALIF, PLIF, and TLIF. The "LIF" in each abbreviation stands for lumbar interbody fusion. The first letter in each abbreviation designates the approach to the vertebral fusion: anterior (front), posterior (back), and transforaminal (side).
ALIF, PLIF, and TLIF all have the same surgical goals. By using these kinds of surgery, the surgeon typically has 3 main goals:
- remove pressure on your spinal nerves (decompression)
- fix the alignment of the spine
- stabilize the spine
Often, it is possible to realign the spine (if the surgeon feels this is necessary); however, as long as pressure is taken off the nerves and the spine is stabilized, the surgery is considered a success.
In the decompression part of the surgery, the surgeon will remove anything that's pressing on a nerve and causing pain. What kind of decompression surgery you have is dependent on what spinal structure is interfering with a nerve. Nerve compression with a spondylolisthesis can come from 4 main sources:
- Bulging or herniated disc: The surgeon will do a discectomy to remove the part of the disc that's compressing the nerve
- Narrowed foramen: At the foramen, the spinal nerves exit the vertebra and head out to various parts of the body. Spondylolisthesis can narrow the foramen when the vertebra shifts forward. The surgeon will do a foraminotomy (making more room for the nerves to pass through the foramen) and/or a vertebral realignment.
- Central spinal stenosis: If the spinal cord and/or spinal nerves don't have enough room as they travel down your spine through the spinal canal, it's called central spinal stenosis. To make more room, the surgeon may do a laminectomy, removing the lamina (think of it as the roof over the back part of your spine).
- Later recess stenosis/Gill fragment: Part of the facet joint can break off in spondylolisthesis—it's then called a Gill fragment. It can press on nerves, so the surgeon will do a facetectomy to remove the Gill fragment.
Removing a disc and/or other spinal structure may make your spine unstable. If the surgeon were to leave that "gap" in your spine, your vertebral column couldn't function properly. It wouldn't be able to support weight or cushion movements as well. To address this, surgeons will stabilize the spine using a fusion. Either from the front (anterior), back (posterior), or side (transforaminal), the surgeon will fill the gap with a bone graft. This can be bone taken from your own body (autograft) or from a donor's body (allograft). There are also synthetic substances that will promote bone growth.
Over time, the bone graft will fuse the vertebrae together. To support the spine as the fusion heals, the surgeon will use spinal hardware such as screws, rods, and cages.
Minimally Invasive Surgery
For patients, minimally invasive surgery is a great development. Minimally invasive surgery is done through several small incisions, as opposed to one big incision—that's how traditional spine surgery is done. Using microscopes and very small instruments, the surgeon can treat spondylolisthesis by doing a decompression and fusion. With a minimally invasive surgery, you'll also lose less blood during the surgery, and the surgeon won't have to cut into your muscles, ligaments, and tendons as much. Because of those two factors, you'll have a shorter hospital stay and a shorter recovery time.
ALIF, PLIF, and TLIF can all be performed minimally invasively.
For spondylolisthesis surgeries, many surgeons use a combination of minimally invasive and open procedures in a technique called "mini open."