Bone screw fixation
Various methods and devices are provided for bone screw fixation. In one exemplary embodiment, the methods and devices provide a bone fixation device that includes a receiving head having a recess adapted to seat a spinal rod therein and a shank extending distally from the receiving head. An anti-rotation mechanism can be located distal of a distal end of the receiving head and around a proximal portion of the shank, and it can be configured to interact with bone to prevent rotation of at least a portion of the bone fixation device relative to the bone.
1. A method of fixing a bone screw to bone, comprising:
implanting a bone anchor into a vertebra, the bone anchor having a receiving head configured for receiving a spinal rod and a shank extending from the receiving head, the receiving head having a substantially rectangular shape such that opposed sidewalls of the receiving head engage adjacent processes of a vertebra to prevent rotation of the receiving head relative to the vertebra; and
after implanting the bone anchor, seating the spinal rod in the receiving head.
2. A method of fixing a bone screw to bone comprising:
inserting the bone screw into bone by rotating a shank of the bone screw in a first direction;
inserting an anti-rotation mechanism through a lumen formed in the shank by rotating the anti-rotation mechanism in a second direction that is opposite to the first direction such that a distal portion of the anti-rotation mechanism engages the bone to thereby prevent rotation of a receiving head of the bone screw relative to the bone;
positioning a spinal connector within the receiving head of the bone screw; and
applying a locking mechanism to lock the spinal connector within the receiving head.
3. The method of claim 2 , wherein inserting the bone screw into the bone comprises inserting the shank into the bone until a head of the shank rests against a surface of the bone.
4. The method of claim 2 , wherein inserting the anti-rotation mechanism comprises inserting the anti-rotation mechanism until the anti-rotation mechanism extends distally beyond a distal-most end of the shank.
5. The method of claim 2 , further comprising locking the anti-rotation mechanism and the shank together to prevent rotation of the anti-rotation mechanism relative to the shank.
6. The method of claim 5 , wherein the locking comprises engaging a tapered head of the anti-rotation mechanism with a tapered portion of the lumen of the shank.