What is the definition or description of: disc replacement?

See below: In essence the adjoining surfaces of a vertebra are cut off to expose good healthy bleeding bone. A metallic implant flat on the bone side and concave and rimmed on the disc side are imlpanted with a metal ball bearing trapped my the concavity and rim complete the implants. As one moves the ball bearing is allowed to move within the precisely machined nd matched plates, confined by the rim.

Currently done in : The cervical or lumbar spine it is the surgical replacement of a poorly functioning intervertebral disc with an artificial one so that motion is maintained. There are a variety of these implants available in terms of there mechanics, materials, and design.