Bone Screw With Channels

Abstract

Embodiments of the invention may prevent or diminish a bone screw from “backing out” from bone. Bone particulate residing in channels of the bone screw may promote bone growth that would reduce the potential of backing out. Furthermore, bone particulate from drilling and tapping functions can cause increased friction. However, by placing bone particulate in channels of the bone screw, potential binding may be reduced resulting in less stress on the screw shaft. Also, breaking of screws during screw insertion may be reduced due to tapering of the screw.

1 . A bone screw comprising:
 a proximal bone screw head portion and a distal tip portion;   a threaded portion, included between the head and tip portions, including a first segment comprising contiguous threads;   a non-threaded portion, included between the head and threaded portions, including first and second channels; and   a cannula coterminous with the head and tip portions and non-coterminous with the threaded and non-threaded portions and the first and second channels;   wherein the head and threaded portions do not include the first and second channels.   
     
     
         2 . The bone screw of  claim 1 , wherein the screw tapers outwardly near the head portion. 
     
     
         3 . The bone screw of  claim 1 , wherein the threaded portion includes an outer thread diameter and an inner thread diameter and the non-threaded portion includes a diameter, the diameter being greater than the inner thread diameter. 
     
     
         4 . The bone screw of  claim 3 , wherein the non-threaded portion is tapered. 
     
     
         5 . The bone screw of  claim 3 , wherein the diameter is greater than the outer thread diameter. 
     
     
         6 . The bone screw of  claim 1 , wherein the first channel includes a distal region that includes a first diameter and a proximal region that includes a second diameter, the second diameter being greater than the first diameter. 
     
     
         7 . The bone screw of  claim 1 , wherein the first channel includes a sharp edge to cut bone during screw insertion. 
     
     
         8 . The bone screw of  claim 1 , wherein the first channel includes a sharp edge to cut bone during screw withdrawal. 
     
     
         9 . The bone screw of  claim 1 , wherein the first channel includes a first sharp edge to cut bone during screw insertion and a second sharp edge to cut bone during screw withdrawal. 
     
     
         10 . The bone screw of  claim 1 , wherein the threaded portion includes a second segment distal to the first segment, the second segment comprising non-contiguous threads and a plurality of cutting flutes. 
     
     
         11 . The bone screw of  claim 1 , wherein the first and second channels are helical. 
     
     
         12 . The bone screw of  claim 1 , wherein the bone screw is a lag screw. 
     
     
         13 . A method comprising:
 creating an incision and producing bone particulate based on partially inserting a cannulated bone screw into a first bone portion;   depositing the bone particulate in first and second channels included entirely in a non-threaded portion of the screw that is proximal to a contiguously threaded portion of the screw;   inserting the screw into a second bone portion;   compressing the first bone portion against the second bone portion based on inserting an outwardly tapered portion of the non-threaded portion of the screw into the first bone portion; and   closing the incision while the bone particulate is deposited in the first and second channels.   
     
     
         14 . The method of  claim 13 , further comprising cutting the first bone portion with a sharp edge included in the first channel during insertion of the screw into the first bone portion. 
     
     
         15 . The method of  claim 13 , further comprising cutting the first bone portion bone with a sharp edge included in the first channel during withdrawal of the screw from the first bone portion. 
     
     
         16 . The method of  claim 13 , further comprising closing the incision while the first channel is adjacent cortical bone to promote integration between cortical bone and the bone particulate included in the first channel. 
     
     
         17 . A bone screw comprising:
 a non-threaded portion, included between a proximal bone screw end and a threaded bone screw portion, including first and second channels; and   a cannula coterminous only with the proximal bone screw end and a distal bone screw end.   
     
     
         18 . The bone screw of  claim 17 , wherein the first and second channels are excluded entirely from the threaded screw portion. 
     
     
         19 . The bone screw of  claim 17 , wherein the non-threaded portion tapers outwardly. 
     
     
         20 . The bone screw of  claim 17 , wherein the first channel includes a sharp edge to cut bone during screw insertion.