Spine fixing device

A spine fixing device comprising:

• a composite body having:
• a base plate;
• and
• a cage configured to be coupled to the base plate;
• a first wing plate configured to be coupled to a first portion of the composite body;
• a second wing plate configured to be coupled to a second portion of the composite body;
• and
• a cover including a first cover and a second cover, respectively coupled to each of the first and second wing plates at a position opposite to the cage with respect to the base plate,
• the first cover having a plurality of first protruding pieces corresponding to a plurality of first screw holes defined on the first wing plate and a central screw hole defined on a center of the base plate, and the second cover having a plurality of second protruding pieces corresponding to a plurality of second screw holes defined on the second wing plate and the central screw hole,
• wherein the first cover is configured to rotate about a first shaft coupled to the first wing plate and position the plurality of first protruding pieces to simultaneously cover the plurality of first screw holes and at least a part of the central screw hole, and the second cover is configured to rotate about a second shaft coupled to the second wing plate and position the plurality of second protruding pieces to simultaneously cover the plurality of second screw holes and at least a part of the central screw hole.