An artificial disc replacement (ADR) includes a pair of opposing endplate components, each attached to one of the upper and lower vertebrae, a cushioning component disposed between the endplate components; and a filler material contained within the cushioning component. The filler material may be a gas,...http://www.google.ca/patents/US20030074076?utm_source=gb-gplus-sharePatent US20030074076 - Artificial intervertebral disc replacements with endplates
