Spinal disc implant. Coloured X-ray of a side view of the neck of a patient with a prosthetic cervical disc (orange). The disc has been implanted to treat osteoarthritis, a degenerative joint disease. The vertebrae (blue blocks) had become compacted. Osteoarthritis damages the cartilage between the vertebrae, moving them closer together. As the cartilage is worn away new bone grows (dark mass between lower 2 vertebrae), a process known as osteophytosis. This limits the flexibility and movement of the neck. The implant will restore some flexibility and movement.