An expandable interbody fusion device in one embodiment includes a cylindrical body (10) defining a hollow interior (17) for receiving bone graft or bone substitute material. The body (10) is divided into a number of branches (24, 26, 40 and 41) connected to one another at a fixed end (20) and separated...http://www.google.de/patents/US6436140?utm_source=gb-gplus-sharePatent US6436140 - Expandable interbody fusion cage and method for insertion
