Composite material spinal implant

A pedicle screw implant construct kit, comprising:

• at least one pedicle screw including a head, said screw comprising composite material including reinforcing filaments embedded in a polymer matrix;
• at least one collar, said collar comprising composite material including reinforcing filaments embedded in a polymer matrix, said collar including at least one recess defining a cavity for receiving a rod, said cavity defining a lumen formed at its ends with a widening relative to a center of said lumen, said widening being between 1% to 10% of a diameter of a rod received within said lumen;
• said collar sized, shaped and configured to be coupled to said head of said pedicle screw;
• an elongated rod sized and shaped for connecting said collar to one or more additional collars, thereby coupling between said at least one pedicle screw and one or more additional screws, said rod comprising composite material including reinforcing filaments embedded in a polymer matrix;
• and
• at least one locking ring, said ring comprising composite material including reinforcing filaments embedded in a polymer matrix, said ring sized and shaped to be positioned over at least portion of said collar and restrict relative movement of one or both of the screw head and the rod relative to said collar, by exerting radial compression force onto said collar.