Spinal fusion is a surgical technique used to combine two vertebrae. Supplementary bone tissue (either autograft or allograft) is used in conjunction with the body's natural osteoblastic processes. This procedure is used primarily to eliminate the pain caused by motion of the vertebrae by immobilizing the vertebrae themselves.
While the two vertebrae that are joined rarely detatch, it does create additional risk of damage to adjacent vertebrae.
Spinal fusion is done most commonly in the lumbar region of the spine, but it is also used to treat cervical and thoracic problems.
Conditions for which spinal fusion is most commonly done:
- degenerative disc disease
- discogenic pain
- spinal tumor
- vertebral fracture
- other degenerative spinal conditions
- any condition that causes instability of the spine
There are two main types of spinal fusion, which may be used in conjunction with each other:
Posterolateral fusion places the bone graft between the transverse processes in the back of the spine. These vertebrae are then fixed in place with screws through the pedicles of each vertebrae attaching to a metal rod on each side of the vertebrae.
Interbody fusion places the bone graft between the vertebrae in the area usually occupied by the intervertebral disc. In preparation for the spinal fusion, the disc is removed entirely. The fusion then occurs between the endplates of the vertebrae. This procedure may be done through the abdomen (Anterior Lumbar Interbody Fusion or ALIF) or through the back (Posterior Lumbar Interbody Fusion or PLIF).
Using both types of fusion in conjunction yields the highest chances of successful fusion. This is known as 360-degree fusion.