Extendable and adjustable trunk fusion system for lordosis of the spine

摘要

The present invention relates to a spinal implant device for placement between vertebral bodies, the device comprising a housing, at least one screw member disposed within the housing, and at least one drive shaft operatively engaging the screw member. . The housing includes a first shell and a second shell. At least the first shell has step tracking including a plurality of discrete risers for receiving the at least one threaded member. The heights of the plurality of individual risers can be varied along with step tracking. The drive shaft may be operable to rotate the at least one threaded member such that the at least one threaded member is movable on the plurality of individual risers. The at least one threaded member includes an external helical thread having a thickness configured to fit into a gap between adjacent individual risers while engageable with the first and second shells, the first and second shells comprising the at least one threaded member and move relative to each other in response to rotation of the at least one screw member to reverse rotation of the at least one screw member, thereby causing expansion of the housing or retraction of the housing after expansion.