There are multiple methods for obtaining a spinal fusion, but the gold standard is a posterolateral gutter fusion.
This type of spinal fusion, which involves placing bone graft in the posterolateral portion of the spine (a region just outside the spine), has a long history and is considered by many surgeons to be the "tried and true" method of spinal fusion.
In a posterolateral gutter fusion, the surgical approach to the spine is from the back through a midline incision that is approximately three inches to six inches long.
- First, bone graft is obtained from the pelvis (the iliac crest), although some form of bone graft substitute may also be used. Most spine surgeons work through the same incision to obtain the bone graft and to perform the spinal fusion.
- Next, the harvested bone graft is laid out in the posterolateral portion of the spine. This region lies on the outside of the spine and is a very vascular area, which is important because the fusion needs blood to supply the nutrients for it to grow.
- A small extension of the vertebral body in this area (transverse process) is a bone that serves as a muscle attachment site. The large back muscles that attach to the transverse processes are elevated up to create a bed to lay the bone graft on. The back muscles are then laid back over the bone graft, creating tension to hold the bone graft in place.