The so called cages are used as a place holder for removed spinal discs. They are small baskets made out of metal, plastic or ceramic. They have the same height as the removed spinal disc and provide for an anatomically correct posture of the spine. Misalignment through degeneration or instability can be reduced or completely eliminated.
Often the surgeon also introduces an additional bony material which is harvested from the patient’s own body. Hereby, the place holder can grow together with the adjacent intervertebral bodies, and thus the vertebral bodies are connected to each other.
This so called fusion stabilizes the affected segment of the spine and fixes it in the correct position. This stabilisation effect can be further secured by screwing a metal plate to the front of the intervertebral body, which is then called a ventral plate osteosynthesis.