Pedicle screws are used sometimes in a spinal fusion to add extra support and strength to the fusion while it heals. Pedicle screws are placed above and below the vertebrae that were fused. A rod is used to connect the screws which prevents movement and allows the bone graft to heal. After the fusion is completely healed, the screws and rods can be removed. Removal isn't necessary unless they cause the patient discomfort.