Spinal Fusion Animation
The Role of Bone Graft in Spine Surgery
This short animation (just a minute long) gives you the basics of spinal fusion. What is it? Why is it done? How is it done? This video will help you understand how spinal fusion works and why it may be used in your spine surgery (if your doctor has recommended surgery to address your back pain).
Why Spinal Fusion Is Done: Disc-related Causes
You have intervertebral discs in between the vertebrae in your spine. They work as shock absorbers, and they facilitate your movements. However, they can become damaged: intervertebral discs can wear out (degenerate), become thinner, or herniate.
When an intervertebral disc is damaged, it can lead to back pain for you. For example, a herniated disc (when the inner, gel-like center of the disc pushes out into the outer cartilage layer) can press on a spinal nerve or the spinal cord. Similarly, if a disc thins, that means the bony vertebrae aren't as separated and cushioned, and they can start to rub on each other or even compress nerves.
A spinal fusion is done to address the back pain caused by the damaged disc.
How a Spinal Fusion Is Done
The damaged intervertebral disc is removed. Sometimes the whole disc is removed; sometimes just part of the disc is removed. Your surgeon will make the best recommendation for how much of the disc to remove, based on your symptoms.
However, with the disc gone, there is a gap in the spine, and if left there, it could lead to spinal instability. That means that your spine wouldn't move and function as it's supposed to, and it could cause more damage and/or pain.
Therefore, the gap where the disc was is filled in. A titanium cage (a special product made for spine surgery) is sometimes used to help maintain the space in between the discs.
The spine will need to form new bone in order to stabilize itself. Bone graft is used. It may come from your own body, or it may come from a bone bank. Another option is to use a synthetic material that's formulated to encourage bone growth.
Whatever bone graft method is used, the hoped-for result is the same: the bone will heal and fuse together, providing spinal stability and addressing the root cause of your back pain.
To further research this topic, you may want to read our detailed article on spinal fusion.