Multi-rod bone attachment member

Abstract

A fixation element for use in orthopedic surgery, particularly spinal surgery is disclosed. The fixation element is capable of being screwed, hooked, or otherwise attached to a bone, and is configured to accommodate two or more rods or other elongated members. The head of the fixation elements thus has multiple places for positioning a rod, either vertically or horizontally spaced from each other.

What is claimed is:  
     
         1 . An apparatus comprising: 
 a one-piece head portion having one or more channels, said channels being configured so that a plurality of elongated members may be connected to said head via one or more of said channels;    at least one holder connected to said head portion, said at least one holder holding at least one of said elongated members within their respective channels; and    an attachment portion connected to said head portion for connecting said head portion to a bone.    
     
     
         2 . The apparatus of  claim 1 , wherein one or more of said channels are oriented in one of (a) open at a back portion of said head portion, and (b) open at a side portion of said head portion.  
     
     
         3 . The apparatus of  claim 1 , wherein said head portion has two channels.  
     
     
         4 . The apparatus of  claim 3 , wherein said channels are substantially parallel, and said head portion is substantially W-shaped.  
     
     
         5 . The apparatus of  claim 4 , wherein each of said channels has approximately the same width or radius.  
     
     
         6 . The apparatus of  claim 4 , wherein one of said channels has a width or radius larger than the other of said channels.  
     
     
         7 . The apparatus of  claim 3 , wherein a female thread is within each of said channels, and said at least one holder comprises a first set screw compatible with said thread in one of said channels and a second set screw compatible with said thread in the other of said channels.  
     
     
         8 . The apparatus of  claim 1 , wherein said attachment portion is integral with said head portion.  
     
     
         9 . The apparatus of  claim 1 , wherein said attachment portion is movably connected with said head portion.  
     
     
         10 . The apparatus of  claim 9 , wherein said attachment portion is at least one of rotatably and multi-axially connected with said head portion.  
     
     
         11 . The apparatus of  claim 10 , wherein said head portion includes an upper end and a lower end and an opening near said lower end, and said attachment portion includes a threaded distal portion and a proximal driving portion, at least a part of said driving portion being sized to fit in said opening.  
     
     
         12 . The apparatus of  claim 11 , wherein said opening has a substantially cylindrical portion, said head portion further including a groove around at least a part of said substantially cylindrical portion, and said apparatus further comprising a snap-ring fitted in said groove, said snap-ring having an inner diameter and an outer diameter configured such that said outer diameter is not smaller than a diameter of said groove when said snap-ring is in an unstressed state, and said inner diameter is smaller than a diameter of said proximal driving portion of said attachment portion.  
     
     
         13 . The apparatus of  claim 12  further comprising a crown member situated in said head portion above said proximal driving portion of said attachment portion, whereby said head portion and said attachment portion can be locked together by pressing down on said crown member.  
     
     
         14 . The apparatus of  claim 12  wherein said proximal driving portion of said attachment members includes a flange.  
     
     
         15 . The apparatus of  claim 1 , further comprising a second attachment portion connected to said head portion for connecting to a bone.  
     
     
         16 . The apparatus of  claim 15 , wherein said second attachment portion includes threads for engaging a bone.  
     
     
         17 . The apparatus of  claim 15 , wherein said second attachment portion is movably connected to said head portion.  
     
     
         18 . The apparatus of  claim 15 , wherein said second attachment portion is at least one of rotatably and multi-axially connected to said head portion.  
     
     
         19 . The apparatus of  claim 15  wherein said second attachment portion includes a fixed prong for engaging a bone.  
     
     
         20 . The apparatus of  claim 1  wherein said head portion has a lower end and an upper end, and said lower end is curved so as to approximate the anatomical curvature of a bone.  
     
     
         21 . The apparatus of  claim 1  wherein said head portion has a medial axis, and said attachment portion is situated along said medial axis.  
     
     
         22 . The apparatus of  claim 1  wherein said head portion has a medial axis, and said attachment portion is situated to one side of said medial axis.  
     
     
         23 . The apparatus of  claim 1  wherein said attachment portion is one of a threaded attachment portion and a hooked attachment portion.  
     
     
         24 . A method comprising: 
 providing a bone-engaging apparatus having an upper head portion and at least one lower attachment portion, said head portion having a plurality of channels so that said head portion is capable of receiving a plurality of elongated members;    connecting said attachment portion of said apparatus to a bone;    inserting an elongated member into one of said channels; and    connecting a holder to said head portion to hold said elongated member in said channel.    
     
     
         25 . The method of  claim 24 , wherein said holder connecting step comprises threading a set screw into the channel into which said elongated member has been inserted until a clamping force is exerted by said set screw on said elongated member sufficient to lock the elongated member with respect to said head portion.  
     
     
         26 . The method of  claim 24 , further comprising inserting a second elongated member into one of said channels.  
     
     
         27 . The method of  claim 26 , wherein said second elongated member is inserted into a channel previously unoccupied by an elongated member.  
     
     
         28 . The method of  claim 27 , further comprising connecting a holder to said head portion to hold said second elongated member in said channel.  
     
     
         29 . The method of  claim 28 , wherein said holder connecting step comprises threading a set screw into the channel into which said second elongated member has been inserted until a clamping force is exerted by said set screw on said second elongated member.  
     
     
         30 . The method of  claim 27 , further comprising: 
 adjusting the bone prior to insertion of the first elongated member; and    further adjusting the bone prior to insertion of the second elongated member.    
     
     
         31 . The method of  claim 26 , wherein said second elongated member is inserted into a channel previously occupied by an elongated member.  
     
     
         32 . The method of  claim 24  further comprising adjusting the relative position of said attachment portion and said head portion prior to a time when said elongated member is locked with respect to said apparatus.  
     
     
         33 . An apparatus comprising: 
 a head portion, said head portion having first and second outer legs and at least one post between said legs, a first channel between said first leg and said post, and a second channel between said second leg and said post, a first thread formed on said first leg and said post and a second thread formed on said second leg and said post;    first and second set screws, said first set screw adapted to be threaded in said first thread to close said first channel, and said second set screw adapted to be threaded in said second thread to close said second channel; and    a bone connection portion connected to said head portion, whereby said apparatus is connected to a bone.    
     
     
         34 . The apparatus of  claim 33 , further comprising at least a first elongated member, wherein at least a portion of said first elongated member occupies at least a portion of said first channel and said first set screw provides a clamping force to hold said elongated member with respect to said head portion.  
     
     
         35 . The apparatus of  claim 34 , further comprising at least a second elongated member, wherein at least a portion of said second elongated member occupies at least a portion of said second channel and said second set screw provides a clamping force to hold said elongated member with respect to said head portion.