EXPANDABLE INTERBODY FUSION CAGE

摘要

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 at an expandable end (18). The expandable cage may be inserted in its substantially cylindrical form and may be expanded by movement of an expansion member (50) to establish lordosis of the spine. The present invention provides an expansion member (50) that interacts with the interior surfaces of the device to maintain the cage in the expanded condition and provide a large internal chamber (17) for receiving bone in-growth material. Methods for insertion of the fusion device are also disclosed.