Theoretical advantages Since artificial hips and knees were introduced in the 1960's, doctors have explored the idea of prosthetic replacements for damaged or degenerated intervertebral discs. The disc is a very complicated joint, so the engineering challenge to partially or fully replace a disc is considerable. The prosthesis is intended to maintain the normal movement between the vertebral bodies and prevent them from collapsing by maintaining the disc space height between the bones. One of the major theoretical advantages of the artificial disc is to preserve the mobility of the patient's adjacent discs and delay the onset of arthritic changes adjacent to a fused level. The procedure can be a substitute for spinal fusion, which eliminates the motion from a painful motion segment by fusing the vertebrae together.
Spinal fusion does tend to place increased stress on the adjacent vertebral segments.
Case example Fig.