The nucleus of an intervertebral disc is replaced with a construct including a distendable sack or balloon which, following insertion at a surgical site, is inflated with a hardenable material and is detached in situ when the injected material has hardened. Preferably, two nested balloons are inserted,...http://www.google.es/patents/US7597714?utm_source=gb-gplus-sharePatente US7597714 - Inflatable nuclear prosthesis
