Monoaxial - uniplanar hybrid screw

A spinal rod anchoring device comprising:

• a body comprising a distal end and a proximal end, wherein a threaded bone anchor extends along a longitudinal axis and is positioned toward the distal end, and a U-shaped head portion is positioned toward the proximal end, wherein the head portion and the threaded bone anchor are fixedly attached;
• a saddle comprising a convex curvature at its lower surface and a concave interior region, wherein the interior region has an open channel therewithin, wherein the convex curvature of the saddle is slidably seated within a concave base of the head portion for arcuate sliding movement of the saddle relative to the head portion, wherein the open channel is sized to allow at least a portion of the saddle to extend beyond the head portion and wherein a spinal connection element is configured to be disposed on the saddle, the concave base and the convex curvature of the lower surface restricting movement of the saddle along a single plane;
• and
• a retaining pin configured to be inserted along the longitudinal axis through the open channel in the saddle and secured in a groove, wherein the groove is centrally positioned within the base of the head portion, wherein the retaining pin slidably secures the saddle to the head portion;
• a closure mechanism configured to be positioned within the head portion;
• wherein the saddle and the head portion comprise two matching radii, and wherein the closure mechanism locks the spinal connection element and the saddle in an angulation relative to the body;
• wherein the U-shaped head portion includes channels disposed about side surfaces of the extensions.

A method comprising:

• fastening two or more spinal rod anchoring devices into two or more vertebrae, wherein each spinal rod anchoring device comprises:
• a body comprising a distal end and a proximal end, wherein a threaded bone anchor extends along a longitudinal axis and is positioned toward the distal end, and a U-shaped head portion is positioned toward the proximal end, wherein the head portion and the threaded bone anchor are fixedly attached;
• a saddle comprising a convex curvature at its lower surface and a concave interior region, wherein the interior region has an open channel therewithin, wherein the convex curvature of the saddle is slidably seated within a concave base of the head portion for arcuate sliding movement of the saddle relative to the head portion, wherein the open channel is sized to allow at least a portion of the saddle to extend beyond the head portion during the arcuate sliding movement and wherein a spinal connection element is configured to be disposed on the saddle;
• a retaining pin configured to be inserted along the longitudinal axis through the channel in the saddle and secured in a groove, wherein the groove is centrally positioned within the base of the head portion, wherein the retaining pin slidably secures the saddle to the head portion;
• a closure mechanism configured to be positioned within the head portion;
• positioning the spinal connection element attached to the first spinal rod anchoring device and;
• interconnecting at least a second rod anchoring device with the spinal connection element;
• wherein the U-shaped head portion includes channels disposed about side surfaces of the extensions.