06419704 is referenced by 566 patents.
Artificial disc replacements for natural intervertebral discs make use of a shaped body having a final volume sized to consume at least a portion of an intervertebral disc space, and a filling within the shaped body enabling the body to cyclically compress and expand in a manner similar to the disc material being replaced. The filling may be a gas, liquid or a gel, in which case the body further includes valve means enabling the body to be filled, preferably following introduction into the disc space. Depending upon the application and other factors, one or more of the bodies may be used in the same disc space, and each may be provided according to different embodiments to distribute compressive stress or to meet other considerations. One or both of the top and bottom surfaces of the shaped body may configured to increase friction so as to maintain the body within the intervertebral space. To increase the strength and/or longevity of the implant, one or more fiber-reinforced layers may be utilized, and may use a bias-ply, a “radial” or bias-belted construction, much like arrangements used in the commercial tire industry.