Extractor for a bone connection element

Abstract

An extractor device is provided to extract an insert to be used with a bone connection element such as a bone plate having at least one opening for a bone screw used with said insert. The extractor device has an outer hollow sleeve having proximal abutment surface being able to engage a surface portion of the bone connection element, and an inner bar having a diameter enabling the insertion of the bar into the hollow sleeve. The bar has a threaded leading end to engage the thread of the insert to be extracted. The hollow sleeve has an inner thread and the inner bar has an outer threaded element for engaging the inner thread of the hollow sleeve. The outer threaded element is positioned with respect to the bar in a longitudinal position to enable the thread at its leading end to extend beyond the proximal abutment surface of the sleeve to be threaded into the insert.

1 . An extractor device for an insert to be used with a bone connection element usable within an implantable orthopedic device having a load-bearing element with at least one opening for receiving a fixation element such as a bone screw with the insert thereon, the extractor device comprising: 
 an outer hollow sleeve, the hollow sleeve comprising a introduction opening at a first end and a proximal abutment surface at a second end engagable with a surface portion of the load-bearing element around the insert, the hollow sleeve further comprising an inner threaded portion between said introduction opening and said abutment surface,    an inner bar, the bar having a diameter enabling the insertion of the bar into said distal introduction opening of the hollow sleeve and comprising a threaded portion engaging the thread of the insert to be extracted,    wherein, alternatively, the inner bar further comprises an outer thread or an intermediate element is provided with a central bore to accommodate said inner bar and comprising an outer thread,    wherein the outer threaded portion is arranged to engage said inner threaded portion of the hollow sleeve,    said outer threaded portion of said inner bar being positioned on the bar or the intermediate element at a longitudinal distance from the insert engaging threaded portion to enable that threaded portion to extend beyond the proximal abutment surface to be threaded in the insert.    
   
   
       2 . The extractor device as set forth in  claim 1 , wherein the insert engaging threaded portion of the bar has a conical thread.  
   
   
       3 . The extractor device as set forth in  claim 1 , wherein an abutment flange connects insert engaging threaded portion with a larger bar section of said inner bar.  
   
   
       4 . The extractor device as set forth in  claim 1 , wherein the inner bar comprises at a first end a handle part having an abutment flange.  
   
   
       5 . The extractor device as set forth in  claim 1 , wherein the hollow sleeve comprises at its second end an enlarged abutment section to engage a surface of the load-bearing element.  
   
   
       6 . The extractor device as set forth in  claim 5 , wherein the hollow sleeve comprises at its first end a hollow handle part.  
   
   
       7 . The extractor device as set forth in  claim 1 , wherein the threads of sleeve and bar, respectively, are located in the first third of the device on moving from said first end of said outer sleeve to said second end.  
   
   
       8 . The extractor device as set forth in  claim 1 , wherein the threads of sleeve and bar or intermediate element have the same handedness than the thread of the tip of the inner bar.  
   
   
       9 . The extractor device as set forth in  claim 1 , wherein the abutment surface is a cylindrical ring, an elliptical ring or a polygonal strip.  
   
   
       10 . A method for extracting an internally threaded insert from an opening in a bone connection element usable within an implantable orthopedic device, such as a bone plate: 
 inserting a bar with a threaded tip and an outer threading into a hollow sleeve having an internal threading for engaging the outer threading of the bar and an abutment tip for engaging the bone plate;    screwing the tip of the bar into the internal threading of the insert to be extracted, preferably until an abutment flange of the tip comes into contact with an upper surface of the insert,    advancing the abutment tip of the hollow sleeve into contact with a surface of the bone connection element, wherein the relative advancement of the hollow sleeve relative to the bar is a longitudinal movement resulting from rotating the engaged inner and outer threads of sleeve and bar;    extracting the insert through further rotation of sleeve or an intermediate element located between the sleeve and the bar, wherein the inner bar or the sleeve, respectively, are maintained in its rotational position, said rotation retracting the bar into the hollow sleeve and exerting a force in a longitudinal direction of the sleeve and bar on the insert against forces holding the insert within the opening in the bone connection element and extracting the insert.    
   
   
       11 . The method as set forth in  claim 10 , wherein the extractor device is assembled by inserting the inner bar into the hollow sleeve from an opening at a first end of the hollow sleeve and relative rotation of the hollow sleeve and bar to engage their inner and outer threads, respectively, until the tip of the bar is extends beyond a second end of the hollow sleeve.  
   
   
       12 . An extraction tool for an internally threaded insert located within an opening in a bone plate comprising: 
 a tubular sleeve having an internal bore with a threaded portion intermediate first and second ends thereof;    a bar for insertion within the internal bore of said tubular sleeve, said bar having a threaded first end and a threaded element located intermediate said first end and a second end of said bar, said threaded element threadably engagable with said threaded outer sleeve portion, said threaded sleeve portion and said threaded element respectively located between the first and second ends of said sleeve and bar such that said threaded first end of said bar extends beyond said first sleeve end when at least a portion of said threaded portions are engaged.    
   
   
       13 . The extraction tool of  claim 12  wherein the first end of said tubular sleeve includes an abutment portion.  
   
   
       14 . The extraction tool of  claim 13  wherein said second end of said tubular sleeve has a drive portion for rotating said sleeve.  
   
   
       15 . The extraction tool of  claim 14  wherein said second end of said bar has a drive portion for rotating said bar.  
   
   
       16 . An insertion device for use with an insert to be used with a bone connection element usable within an implantable orthopedic device, the insert having at least one threaded opening for a fixation element, the insert having inwardly deformable sidewalls for engaging walls of said opening, the insertion device comprising: 
 a bar having a threaded portion at one end thereof to engage the thread in the opening of the insert to be inserted,    wherein a length of the threaded end portion of said inner bar is shorter than a thickness of the insert to avoid engagement of the threaded bar portion with the deformable sidewalls of said insert.    
   
   
       17 . An insert for use with an orthopaedic device such as a bone plate with at least one opening for receiving a fixation element engagable with said insert, the insert comprising an external surface that is at least partially complementary to an internal shape of the opening, wherein the insert has a central threaded through-bore for mounting a body of the fixation element, and in which the insert has resilient sidewalls for holding the insert in the opening which sidewalls have a thickened part which can be positioned adjacent an internal portion of said opening.  
   
   
       18 . The insert as set forth in  claim 17  wherein said thickened part tapers inwardly towards said through-bore.