Radiolucent screw with radiopaque marker

Abstract

A bone screw includes an elongate shaft extending longitudinally between a proximal end and an opposing distal end. The shaft bounds a first passageway at least partially extending between the proximal end and the distal end. The shaft is comprised of a radiolucent material. A core is disposed within the first passageway of the shaft. The core can be comprised of a radiolucent or radiopaque material. A head is either integrally formed with or secured to the proximal end of the shaft or the proximal end of the core. The head can also bound a second passageway that extends through the head and is aligned with the first passageway. The core can also be disposed within the second passageway.

What is claimed is: 
     
         1 . A bone screw comprising:
 an elongate shaft extending longitudinally between a proximal end and an opposing distal end, the shaft bounding a first passageway at least partially extending between the proximal end and the distal end, the shaft being comprised of a radiolucent material; and   a core disposed within the first passageway of the shaft, the core being comprised of a radiopaque material.   
     
     
         2 . The bone screw as recited in  claim 1 , wherein the shaft comprises an exterior surface having a radially outwardly projecting helical thread formed thereon. 
     
     
         3 . The bone screw as recited in  claim 1 , further comprising a head or a collar rigidly secured to the proximal end of the shaft. 
     
     
         4 . The bone screw as recited in  claim 3 , wherein the head or the collar is comprised of a radiopaque material. 
     
     
         5 . The bone screw as recited in  claim 3 , wherein the head or the collar is comprised of a metal. 
     
     
         6 . A bone screw comprising:
 an elongate shaft extending longitudinally between a proximal end and an opposing distal end, the shaft bounding a first passageway at least partially extending between the proximal end and the distal end, the shaft being comprised of a radiolucent material;   a core disposed within the first passageway of the shaft, the core being comprised of a radiopaque material that comprises a metal, that shaft being comprised of a pre-fabricated sheet comprised of the one or more radiolucent fibers and an adhesive that encircles the radiopaque core so that the one or more radiolucent fibers radially encircling the core;   an enlarged head disposed at an end of the core and being comprised of the same radiopaque material as the core, the core and the head being integrally formed as a single, one piece, unitary member, the enlarged head having a maximum diameter that is larger than a maximum diameter of the core; and   a helical thread recessed into the pre-fabricated sheet encircling the radiopaque core.   
     
     
         7 . The bone screw as recited in  claim 6 , wherein the head is secured to the proximal end of the shaft. 
     
     
         8 . The bone screw as recited in  claim 6 , wherein the first passageway extends completely through the shaft. 
     
     
         9 . The bone screw as recited in  claim 6 , wherein the core has an outer surface with a projection projecting therefrom. 
     
     
         10 . The bone screw as recited in  claim 6 , wherein the head and the core have an interior surface that bound a passageway that longitudinally extends through the core and the head. 
     
     
         11 . The bone screw as recited in  claim 6 , wherein the head comprises an annular shoulder, an annular head portion, and a neck formed therebetween, the neck inwardly constricting relative to the annular shoulder and the annular head. 
     
     
         12 . The bone screw as recited in  claim 6 , wherein the shaft encircles the core but does not encircle the head. 
     
     
         13 . The bone screw as recited in  claim 6 , wherein the core extends the entire length of the shaft. 
     
     
         14 . A method of manufacturing a bone screw, the method comprising:
 forming an elongated shaft about a core, an enlarged head being integrally formed on an end of the core, the shaft having a longitudinal axis extending between a proximal end and an opposing distal end with a first passageway that extends completely through the shaft along the longitudinal axis, the core being disposed within the first passageway and extending along the longitudinal axis, the shaft being comprised of a radiolucent material that includes one or more radiolucent fibers that radially encircles the core, the core and head being comprised of a radiopaque material, wherein the shaft is formed by:
 winding the one or more radiolucent fibers having an adhesive thereon about the radiopaque core; or 
 winding a sheet comprised of the one or more radiolucent fibers and an adhesive about the radiopaque core; and 
   forming a helical thread on an exterior surface of the shaft by removing a portion of the exterior surface of the shaft.   
     
     
         15 . The bone screw as recited in  claim 14 , wherein the one or more radiolucent fibers radially encircle the core in a helical pattern that extends along a length of the core. 
     
     
         16 . The bone screw as recited in  claim 14 , wherein the radiopaque material of the core is comprised of titanium, stainless steel, tungsten, cobalt based alloys, cobalt chrome alloys, nickel titanium alloys, platinum, iridium, gold, barium and alloys thereof. 
     
     
         17 . The method as recited in  claim 14 , wherein the step of removing a portion of the exterior surface of the shaft is accomplished through the use of a grinder, lathe or cutting tool. 
     
     
         18 . The method as recited in  claim 14 , wherein the one or more radiolucent fibers radially encircle the core in a helical pattern that extends along a length of the core. 
     
     
         19 . The method as recited in  claim 14 , wherein the core and the head are comprised of a metal.