A combination of metal screws and rods (hardware) creates a solid "brace" that holds the vertebrae in place. These devices are intended to stop movement from occurring between the vertebrae. These metal devices give more stability to the fusion site and allow the patient to be out of bed much sooner.
Special screws called "pedicle screws" are placed through the pedicle bone on the back of the spinal column. The screw inserts through the pedicle and into the vertebral body, one on each side. The screws grab into the bone of the vertebral body, giving them a good solid hold on the vertebra. Once the screws are placed they are attached to metal rods that connect all the screws together. When everything is bolted together and tightened, this creates a stiff metal frame that holds the vertebrae still so that healing can occur. The bone graft is then placed around the back of the vertebrae.