Here is a drawn out picture of what it looks like. you'll see it covers 1 level and the screws are holding that segment of the spine in place. There are currently two primary alternative sources for the bone needed for the spinal fusion. Traditionally, some of the patient's own bone has been harvested from the hip bone. This technique produces excellent results for the fusion but has a longer and more painful recovery. In 2003, the FDA approved a genetically engineered bone substitute for use in spinal fusions. This method converts stem cells into bone forming cells and stimulates rapid growth of bone at the targeted site. Using the synthetic material eliminates the need for harvesting the patient's own bone and speeds up the fusion process. The synthetic is the one they used on me. And I am happy for less pain!!
This is a picture of my own xray like you would be looking straight at my spine. It's not a very good quality picture because I took it with my cellphone.