Bio-flexible spinal fixation apparatus for preventing fatigue fracture

A bio-flexible spinal fixation apparatus, comprising:

• a screw pike that includes a head part that has a receiving part penetrating in both sides and female threads formed on an inner circumferential surface of the receiving part and grooves formed in parallel at a bottom portion and a screw that extends to a bottom surface of the head part and is configured to be inserted into a spinal segment;
• a rod that has a straight part seated in the groove of the screw pike and a coil part wound to be inclined by a specific angle based on a center separated by a predetermined distance with an eccentricity from a center of the straight part;
• a set screw that has a fixing groove formed in the central portion and is fastened to the female thread of the head part of the screw pike to pressurize and fix the rod, wherein the set screw has the coupling hole smaller in size than a fixing groove at a lower end of the central portion;
• and
• a washer that has a spherical projection provided on an upper side of the central portion to fit into a coupling hole of the set screw and has a spherical groove having a size receiving a spherical surface of the rod formed on the bottom surface to uniformly share a vertical load applied by a tightening force of the set screw to the flat surface of the rod.

A bio-flexible spinal fixation system comprising:

• first, second, and third pedicle screw arrays, each including:
• pedicle screws configured to be arranged vertically on each side of a center line of a human body, and head parts having a plurality of opening grooves;
• first and second rod arrays, each seated in one of the plurality of opening grooves of the head parts of the pedicle screws in the first, second and third pedicle screw arrays, wherein the rod arrays connect the pedicle screw arrays in a segmented form;
• a fixing cap, fastened to the head parts of the pedicle screws in the first, second and third pedicle screw arrays, fixing the first and second rods of the rod arrays to prevent the first and second rods from being separated from the opening grooves;
• wherein each of the first and second rods comprises:
• a straight part,
• a coil part formed at a central portion of the straight part;
• whereby the coil part is wound eccentrically in one direction while extending upward from the center of the straight part;
• whereby the coil part is inclined in either the medial or lateral direction relative to an imaginary centerline of each pedicle screw when the surgical patient is in a prone position on an operating table.