Method and apparatus for providing an expandable spinal fusion cage

Abstract

The spinal fusion cage of the invention comprises two opposing end plates, and three opposing collapsible legs. The two opposing end plates and three opposing collapsible legs are adapted to be configured into an expanded cage from a collapsed configuration. The expanded cage assumes a predetermined rigid shape and volume for disposition between two adjacent vertebrae. The collapsed configuration of the cage is adapted for posterior insertion into the disk space. The apparatus further comprises locking means for at least temporarily locking the legs and maintaining the cage in an expanded configuration. One of the legs is medially disposed on a first side of the cage and the other two are laterally disposed with respect to the end plates on a second side. The three legs have differing lengths so that the cage assumes a wedge-shaped envelope in the expanded configuration. The wedge-shaped envelope reestablishes a predetermined lordosis between fused vertebrae. The invention includes an inserter comprised of a tubular member and holding clamp disposed on the distal end of the tubular member. The holding clamp holds the cage in the collapsed configuration for insertion into a confined surgical theater. The cage is then reconfigured to the expanded configuration using the inserter. Further activation of the inserter causes the cage to be temporarily locked into the expanded configuration.

Dependencies are inferred from the claim text.