Patent attributes
The expandable intervertebral cage includes an upper block and a lower block movable relative to each other. The lower block defines a cam surface and the upper block defines a cam follower surface. Linkages connecting the upper and lower blocks maintain contact between the cam and cam follower surfaces. By rotating a screw, which extends through the lower block, the cam follower surface of the upper block is pushed along the cam surface of the lower block, thus resulting in vertical and horizontal displacement between the upper and lower blocks. Proximal and distal yokes in the blocks define protrusions in the cam and cam follower surfaces. When the cam follower surface slides along the cam surface, the protrusions cause vertical and angular displacement in the upper block, providing distraction, reduction, and lordosis of attached vertebra.
