Bone Compression and Fixation Devices

Abstract

A bone screw, for drawing first and second bone fragments together, includes a shaft having a distal section and a proximal section. The distal section has a first external male screw thread and a minor diameter. The proximal section has a second external male screw thread. A major diameter of the distal section is larger than a major diameter of the proximal section. The bone screw includes a sleeve that has an internal female screw thread configured to mate with the second male screw thread. A distal portion of the sleeve has an outer diameter. The outer diameter is equal to or smaller than the minor diameter of the distal section of the shaft.

I claim: 
     
         1 . A bone screw for drawing first and second bone fragments together, comprising:
 a shaft having a distal section and a proximal section, the distal section having a first external male screw thread and a minor diameter, the proximal section having a second external male screw thread, a major diameter of the distal section being larger than a major diameter of the proximal section; and   a sleeve having an internal female screw thread configured to mate with the second male screw thread, a distal portion of the sleeve having an outer diameter, the outer diameter being equal to or smaller than the minor diameter of the distal section of the shaft.   
     
     
         2 . The bone screw of  claim 1 , wherein the sleeve is configured to receive a tool to rotate the shaft and sleeve together when the shaft is driven into a first bone fragment or rotate the sleeve relative to the shaft to draw a second bone fragment toward the first bone fragment. 
     
     
         3 . The bone screw of  claim 1 , wherein a pitch of the first external male screw thread is larger than a pitch of the second external male screw thread. 
     
     
         4 . The bone screw of  claim 1 , wherein the distal portion of the sleeve is tapered. 
     
     
         5 . The bone screw of  claim 1 , wherein the sleeve includes two or more external longitudinally extending slots configured to engage a tool. 
     
     
         6 . The bone screw of  claim 1 , wherein the distal portion of the sleeve is smooth. 
     
     
         7 . The bone screw of  claim 1 , wherein the shaft is cannulated. 
     
     
         8 . The bone screw of  claim 1 , wherein the shaft includes at least one aperture along a length of the shaft in fluid communication with a hollow center of the shaft. 
     
     
         9 . The bone screw of  claim 1 , wherein the shaft includes a plurality of apertures along a length of the shaft, the plurality of apertures being in fluid communication with one another. 
     
     
         10 . A bone screw system for drawing first and second bone fragments together, comprising:
 a bone screw including:
 a shaft having a distal section and a proximal section, the distal section having a first external male screw thread, the proximal section having a second external male screw thread, a major diameter of the distal section being larger than a major diameter of the proximal section; and 
 a sleeve having an internal female screw thread engageable with the second male screw thread, the sleeve being configured to receive a first tool for rotating the shaft and sleeve together and a second tool for rotating the sleeve relative to the shaft; 
   a tool including:
 a first tool portion configured to rotate the sleeve relative to the shaft; and 
 a second tool portion configured to rotate the shaft and the sleeve together. 
   
     
     
         11 . The bone screw system of  claim 10 , wherein the second tool portion includes a threaded distal end that is engageable with the internal female screw thread and abuts the proximal section. 
     
     
         12 . The bone screw of  claim 10 , wherein the second tool portion extends through the first tool portion when rotating the shaft and sleeve together and the second tool portion is withdrawn from the first tool portion when rotating the sleeve relative to the shaft. 
     
     
         13 . A wire device for drawing first and second bone fragments together, comprising:
 a wire having an external male thread; and   a sleeve having an internal female thread configured to mate with the external male thread.   
     
     
         14 . The wire device of  claim 13 , wherein the sleeve is configured to slide over the external male thread in a distal direction without rotating the sleeve relative to the wire. 
     
     
         15 . The wire device of  claim 14 , wherein the sleeve includes two or more axially extending slots to form two or more phalanges. 
     
     
         16 . The wire device of  claim 13 , wherein the wire includes a distal section and a proximal section, the distal section having a first external male screw thread, the proximal section having a second external male screw thread, a major diameter of the distal section being larger than a major diameter of the proximal section. 
     
     
         17 . The wire device of  claim 16 , wherein a pitch of the first external male screw thread is larger than a pitch of the second external male screw thread. 
     
     
         18 . The wire device of  claim 13 , wherein the sleeve includes two or more radially extending projections. 
     
     
         19 . The wire device of  claim 13 , wherein a distal portion of the sleeve has a diameter equal to or smaller than a minor diameter of the wire. 
     
     
         20 . The wire device of  claim 13 , wherein the sleeve is tapered. 
     
     
         21 . A method for drawing first and second bone fragments together, comprising:
 screwing a wire having an external male thread into a first bone fragment;   sliding a sleeve having an internal female thread configured to mate with the external male thread along the wire without rotating the sleeve relative to the wire to abut a second bone fragment;   rotating the sleeve relative to the wire to draw the second bone fragment toward the first bone fragment, a proximal portion of the wire extending proximally from the second bone fragment and the sleeve; and   cutting and removing the proximal portion of the wire from the remainder of the wire.   
     
     
         22 . A bone fixation device comprising:
 a distal end configured to attached to a first bone section and a proximal end configured to attached to a second bone section,   a flexible body secured to the distal end and movably attached to the proximal end; and   a plurality of cannulated rigid segments surrounding the body,   wherein the segments are spaced and allow the body to flex when the body is in a first position relative to the proximal end and   wherein the segments abut and prevent the body from being flexed when the plate is moved from the first position to a second position relative to the proximal end.   
     
     
         23 . The bone fixation device of  claim 22 , wherein the body is flexible along a first plane and rigid along a second plane, the first plane being orthogonal to the second plane. 
     
     
         24 . The bone fixation device of  claim 22 , wherein the body has a rectangular cross section. 
     
     
         25 . The bone fixation device of  claim 22 , wherein the body is threadably attached to a radially rotatable, axially fixed sleeve in the proximal end. 
     
     
         26 . The bone fixation device of  claim 22 , wherein each segment includes a projection that mates with an indent of an adjacent segment in the second position. 
     
     
         27 . The bone fixation device of  claim 22 , wherein the segments are cylindrically shaped. 
     
     
         28 . The bone fixation device of  claim 22 , wherein the body includes at least one aperture and the proximal end includes at least one aperture, the at least one aperture of the body aligning with the at least one aperture of the proximal end in the second position.