| 摘要 |
Intervertebral cages, and methods of introducing the same, require few, if any, structural components within the cage itself, thereby providing a maximum volume for bone-graft filler. Cages according to the invention may passively expand to fill a volume within the disk space, or active expansion means may be provided. In terms of a passive expansion, at least a portion of the frame may be composed of a shape-memory material, causing the cage to naturally expand from the compressed to the expanded state once the cage is positioned within the intervertebral space. In either case, locking means are provided to maintain the shape of the cage once in position. An alternative embodiment includes first and second components, each having a compressed state which consumes a compressed volume associated with insertion of the component into an intervertebral space, and an expanded state which consumes a greater volume when the component is positioned within the intervertebral space. In terms of an active expansion, an externally accessible mechanism may be used to increase the anterior height once the cage is positioned within the intervertebral space. In all embodiments, connection means may be provided for interconnecting a plurality of cages together within the same intervertebral space.
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