Spinal fusion is a surgical procedure used to correct problems with the small bones in the spine (vertebrae). It is essentially a "welding" process. The basic idea is to fuse together the painful vertebrae so that they heal into a single, solid bone.

This article focuses on just the surgical component of anterior lumbar interbody fusion. For a complete overview of spinal fusion, including approaches, bone grafting, complications, and rehabilitation, please go to Spinal FusionSpinal Fusion (topic.cfm?topic=A00348).

An interbody fusion involves removing the intervertebral disk. When the disk space has been cleared out, a metal, plastic, or bone spacer is implanted between the two adjoining vertebrae.

These spacers, or "cages", usually contain bone graft material. This promotes bone healing and facilitates the fusion. After the cage is inserted, surgeons often use metal screws, plates, and rods to further stabilize the spine.

An interbody fusion can be performed using a variety of different approaches.

In an anterior lumbar interbody fusion (ALIF), the procedure is performed from the front. With this approach, the organs and blood vessels must be moved to the side. This allows your surgeon to access the spine without moving the nerves.

(Left) This X-ray of the lumbar spine shows decreased disk space between the vertebrae. (Right) An interbody cage has been inserted with an ALIF procedure. The bone graft is contained within the metallic cage and cannot be seen.