Spine | Anterior Lumbar Interbody Fusion with Bone Graft & Plate
A lumbar fusion is when two or more vertebrae in the low back are fused together to create a solid bridge of bone between the vertebrae and across the disc space. A fusion is usually performed to eliminate movement between vertebrae and stabilize a painful or unstable segment of the spine. An anterior lumbar fusion approaches the spine through the abdomen to accomplish the fusion.
Anterior lumbar fusion can be used in many situations but frequently is performed to increase the chances of fusion in difficult situations, such as patients who have had prior failed posterior fusion surgery. Anterior fusion also allows for better disc height restoration in patients with collapsed discs. Anterior fusion is not as effective when there is significant spinal stenosis as it cannot directly decompress the nerve roots.
After general anesthesia, an incision is made through your abdominal muscles. The surgery is then done by moving the abdominal contents over and then identifying the great vessels, called the aorta and the inferior vena cava. These are also carefully retracted over the spine. At this point, we are able to look directly at the front part of the spine and have excellent access to the disc spaces in the spine. The disc is then removed as completely as possible and replaced by a cage, a metal or carbon fiber device, filled with bone or bone growth proteins.
In a posterior lumbar fusion, the fusion is done through the back part of the spine. The muscles are dissected from the spine. The bony surfaces of the spine are exposed and small pieces of bone are laid across the back part of the spine. In an anterior fusion, the surgery is done through the front of the spine, which makes it necessary for us to go through your abdomen. In the anterior fusion, the bone graft is packed directly between the vertebral bodies. It is generally felt that if one can obtain a solid anterior fusion there is a mechanical advantage as most of the force of the spine is directed through the front part of the spine.
There are several risks to the operation of which you should be aware. One of these is that the bone placed between your vertebrae might not fuse and there would be a nonunion of this area. Fusion occurs in over 90% of nonsmokers with anterior lumbar fusion, but rates in smokers are decidedly lower. Nonunion, or failure of fusion, can require more surgery.
Infection rates average 1-2% and may require further surgery and antibiotics. Spinal fluid leaks occur in about 1% of cases and may require a longer hospitalization while the leak heals. Nerve damage is rare, averaging less than 1%, and is generally limited to one nerve going to one leg and not a cause of paralysis.
Major organ or vessel damage is rare.
Finally, in 2–3% of men retrograde ejaculation can result from nerve damage, potentially producing sterility.
Over 80% of patients see a significant reduction in their preoperative pain.
Lumbar fusion is generally an elective surgery. Therefore, it is your choice to proceed based on your current level of discomfort and disability. We recommend that you do not have surgery if you can live with your current level of pain or can make changes in your lifestyle to decrease the pain. If you have made a valiant effort and the pain still persists, surgery may be your next step.