When a vertebra slips out of proper alignment, the discs can be damaged. To correct this, a spinal surgeon removes the damaged disc. The slipped vertebra is brought back into line. This relieves pressure on the spinal nerve.
The empty disc space is filled with carbon fiber supports called cages. A disc-shaped bone graft may be used instead of cages.
The realigned vertebrae are held in place by a small rod that is attached with pedicle screw. This adds stability to the spine.