A Minimally Invasive Approach to Traditional Fusion Procedures
Because spine surgeons are constantly seeking new ways to perform spine surgery in the safest, most effective way, recovery from spine surgery today can be less painful and more rapid. A technique called axial lumbar interbody fusion (AxiaLIF)—a minimally invasive approach to traditional lumbar fusion procedures—is designed to achieve these goals for certain spine conditions.
AxiaLIF is done in line with your spine, just below your tailbone. It's known as a "trans-sacral" procedure, which means it's performed through the sacrum along the axis (line of your spine). It is done perpendicular to your intervertebral disc.
Your surgeon may prefer this approach to an anterior (front) approach (eg, anterior lumbar interbody fusion or a posterior approach (PLIF/TLIF) because it is the least invasive surgery at the L5-S1 level. (L5 is the last vertebra in your lumbar spine—your low back—and S1 is the first vertebra in your sacrum.)
Also, besides being one of the least invasive fusion procedures, there are several other benefits of AxiaLIF:
- Less scarring
- Less blood loss
- Less risk of infection
- Quicker return to work and other activities
- Can be performed on an outpatient basis
When Is AxiaLIF Used?
All AxiaLIF procedures are performed at the L5-S1 disc space. Some procedures also include the L4-L5 disc space. AxiaLIF is used to restore disc height in those disc spaces and to stabilize your spine.
Normally, there's a natural amount of space for each of your discs between each of your vertebra. But if one of your discs becomes too thin (because of aging or an injury), your surgeon may need to restore its height to a normal state to relieve your symptoms. AxiaLIF accomplishes this goal.
This procedure is most commonly performed in people who have:
- degenerative disc disease
- low-grade spondylolisthesis
- spinal stenosis
- pseudoarthrosis (failed fusion from a previous surgery)
How AxiaLIF Is Done
For this procedure, you'll be lying on your stomach, and you'll most likely be under general anesthesia.
Unlike some traditional techniques, with AxiaLIF, your surgeon can't actually see the disc he or she is operating on. Instead, your surgeon will use a special type of x-ray, such as fluoroscopy, to help guide him or her throughout your surgery.
Your surgeon will make one 1-inch incision to access your L5-S1 disc space. Using a guide pin, your surgeon will gently push through your fat tissues until he or she reaches the top of your sacrum (the lowest level of your spine). Then, using a series of dilators and a small drill, your surgeon will create a working channel (called a transosseous channel). He or she will perform the surgery through that channel.
Your surgeon will remove your disc by performing a discectomy.
When he or she removes your disc, there's an empty space. This space needs to be filled with something because if it's not, your spine can become unstable. That means you can be more prone to excessive movement and perhaps injury. As a result, your surgeon can use fusion to help stabilize your spine.
He or she will fill this empty space with bone graft, a substance that stimulates bone growth and facilitates fusion between your vertebrae. Bone graft is created with actual bone or a biologic substance. When it's from your own body, it's called autograft; when it's from a donor's body, it's called allograft. Biologic substances (eg, bone morphogenetic protein)—man-made bone graft substitutes—can also help facilitate the fusion process.
A specially threaded screw that acts like a cage will also be inserted to help distract your vertebral bodies by pushing apart the 2 vertebrae (L5-S1) to restore your disc height. Then more bone graft is inserted into tiny holes in the threaded cage to facilitate fusion.
Although this is usually enough to stabilize your spine, you might need more support. If that's the case, your surgeon may use pedicle screws or facet screws to help with further stabilization as your bones fuse to form permanent support. Fusion typically takes fewer than 9 months.
The entire AxiaLIF procedure takes about 45 minutes to perform.
Even though AxiaLIF has fewer complications than traditional fusion approaches, it's still spine surgery, so there are still risks for this procedure:
- Injury to your bowel or bladder
- Injury to your blood vessels
- Bone graft may not properly fuse, which may require an additional surgery
- Your bones may collapse on the cage or screw
- Screws (if used) can shift
Your doctor will let you know when you're ready to return to your regular activities, but most patients who have the AxiaLIF procedure can rapidly return to daily activities, usually within 2 weeks after surgery.