Superior and/or inferior facets of one or more facet joints may be replaced by superior and/or inferior facet joint prostheses. In one embodiment, a kit of superior or inferior prostheses is provided, in which the prostheses have at least two dimensions that vary among members of the kit independently...http://www.google.de/patents/US20090024168?utm_source=gb-gplus-sharePatent US20090024168 - LINKED BILATERAL SPINAL FACET IMPLANTS AND METHODS OF USE
