A spinal fusion is a surgical procedure that joins your spinal segments together for the purpose of eliminating motion at that segment. The overall goal of this type of procedure is to decrease your pain.
Watch: Spine Fusion Surgery Video
Our video walk-through can help you better understand the gold standard of spinal fusions, the posterolateral gutter fusion.
A posterolateral gutter fusion is performed on your lower back (lumbar spine) to relieve pain from lumbar degeneration.
The image above pictures the spinal segments where a posterolateral gutter fusion is performed: L1-L2 through L5-S1 at the bottom of your spine. The segments that most often require a fusion are at L4-L5 and L5-S1.
Watch: Lumbar Spine Anatomy Video
To stop the motion at your affected segment, a bone graft is placed along the posterolateral portion of your back (shown above in purple).
To begin, your surgeon will make a 3 to 6 inch incision in the midline of your back, and then retract the muscles surrounding your spine. In the above image, the muscles are shown in purple; and you can see the exposed spine.
At this time, your surgeon may perform a laminectomy to remove any bone that is irritating your nerves.
Next, your surgeon will retrieve bone for the graft from your iliac crest, which is the uppermost part of the back of your pelvis. Your surgeon may be able to retrieve the bone graft through the original incision on the midline of your back.
In some cases, a synthetic or cadaver bone graft may also be used.
Once the bone graft is ready, your doctor will expose the posterolateral area of your back by removing the muscles that attach to the transverse processes.
This area of your body has a high number of blood vessels, which are crucial for helping your body generate new tissue for the bone graft. Your surgeon will place the bone graft morsels (shown above as reddish cells) on the exposed posterolateral area.
Your surgeon will then place your muscles back down over your graft. This generates tension that will hold it in place as your body heals.
This process is then repeated on the other side of your spine so that both sides will fuse together.
In certain cases, your surgeon may use pedicle screws and rods to provide additional stability for your bone while it is fusing.
Results from a posterolateral gutter fusion
The image above pictures the result of the fusion after several months of healing: The body's natural healing responses have helped the bone graft and adjacent vertebral bodies fuse into a single bone.
A successful fusion surgery is partially dependent on several factors, including the skill of your surgeon and leading a reasonably healthy lifestyle.
The main risk with this type of procedure is that a solid fusion will not be obtained.
Failure rates are higher for patients who:
- Have had prior surgery
- Smoke or are obese
- Have multiple level spine fusion surgery
- Have been treated with radiation for cancer.