Intramerdullary canal diameter reducer background of the invention

Abstract

A canal diameter reducer ( 20 ) is placed within the intramedullary canal ( 21 ) alongside an intramedullary rod ( 23 ) to stabilize the intramedullary rod and prevent toggling and/or misalignment due to shear. The canal reducer is an elongated block ( 19 ) which may be guided into position by a guide wire and may be held in position during insertion of the rod by a suture ( 27 ) extending through hole 31. The reducer ( 20 ) is inserted through an entry opening ( 24 ) formed in the end of the fractured bone ( 22 ). The canal reducer may be fabricated from allograft bone or xenograft bone.

1 . A canal diameter reducer adapted to be placed within an intramedullary canal comprising a block of material having a shape, size and dimension appropriate for being located within the intramedullary canal alongside an intramedullary member, said block stabilizing the intramedullary member and preventing toggling and/or misalignment due to shear.  
   
   
       2 . A canal diameter reducer adapted to be placed within an intramedullary canal comprising an elongated block having a concave inner surface extending longitudinally of said block, said block being adapted to be placed in the intramedullary canal between an intramedullary member and the wall of the canal to prevent toggling and misalignment due to shear, said block being adapted to contact said intramedullary member with said concave inner surface.  
   
   
       3 . A canal diameter reducer adapted to be placed within an intramedulary canal comprising a block having a convex outer surface which is provided with a series of projections for engagement with bone to prevent movement relative to bone, said block being adapted to be placed in the intramedullary canal between an intramedullary member and the wall of the canal with said series of projections in engagement with the wall of the canal, said block being adapted to engage said intramedullary member to prevent toggling and misalignment due to shear.  
   
   
       4 . A canal diameter reducer adapted to be placed within an intramedullary canal comprising an elongated block having tapered ends and a longitudinally extending aperture sized for reception of a guide wire, said block also having at least one hole therethrough for attachment of a suture, said block being adapted to be placed in the intramedullary canal between an intramedullary member and the wall of the canal to prevent toggling and misalignment due to shear.  
   
   
       5 . A canal diameter reducer adapted to be placed within an intramedullary canal comprising an elongated bock having tapered ends and a concave inner surface extending longitudinally of said block, said block having a convex outer surface, said tapered ends extending from said convex outer surface to said concave inner surface and tapering in such a manner as to cause the outer surface to extend longitudinally a greater distance than said inner surface, said block being adapted to be placed in the intramedullary canal between an intramedullary member and the wall of the canal to prevent toggling and misalignment due to shear, said block being adapted to contact said intramedullary member with said concave inner surface.  
   
   
       6 . The canal diameter reducer of  claim 2  wherein said block has a convex outer surface which is provided with a series of projections for engagement with bone to prevent movement relative to bone, said block being adapted to be placed in the intramedullary canal between an intramedullary member and the wall of the canal with said series of projections in engagement with the wall of the canal.  
   
   
       7 . The canal diameter reducer of  claim 4  wherein said block has a convex outer surface which is provided with a series of projections for engagement with bone to prevent movement relative to bone, said block being adapted to be placed in the intramedullary canal between an intramedullary member and the wall of the canal with said series of projections in engagement with the wall of the canal.  
   
   
       8 . The canal diameter reducer of  claim 4  wherein block has a concave inner surface extending longitudinally of said block, said block being adapted to contact said intramedullary member with said concave inner surface.  
   
   
       9 . A canal diameter reducer adapted to be placed within an intramedullary canal comprising an elongated block having a concave inner surface extending longitudinally of said block, said block having a convex outer surface which is provided with a series of projections for engagement with bone to prevent movement relative to bone, said block having tapered ends which extend from said convex outer surface to said concave inner surface and taper in such a manner as to cause the outer surface to extend longitudinally a greater distance than said inner surface, said block having a longitudinally extending aperture sized for reception of a guide wire, said block also having at least one hole therethrough for attachment of a suture, said block being adapted to be placed in the intramedullary canal with said concave inner surface in contact with an intramedullary member to prevent toggling and/or misalignment due to shear.  
   
   
       10 . The canal diameter reducer of  claim 1  wherein said block has a series of holes therethrough and is bioresorbable.  
   
   
       11 . The canal diameter reducer of  claim 1  which is fabricated from allograft bone.  
   
   
       12 . The canal diameter reducer of  claim 1  which is fabricated from xenograft bone.  
   
   
       13 . The canal diameter reducer of  claim 2  wherein said block has a series of holes therethrough and is bioresorbable.  
   
   
       14 . The canal diameter reducer of  claim 3  wherein said block has a series of holes therethrough and is bioresorbable.  
   
   
       15 . The canal diameter reducer of  claim 4  wherein said block has a series of holes therethrough and is bioresorbable.  
   
   
       16 . A process for reducing the toggle and/or misalignment of a fracture fixed with an intramedullary member which comprises forming an entry opening in the fractured bone in the end of the bone leading into the intramedullary canal, inserting a block through the entry opening into the intramedullary canal to reduce the diameter of the intramedullary canal, and inserting an intramedullary member through the opening into the intramedullary canal to a position alongside said block.  
   
   
       17 . The process of  claim 16  additionally comprising attaching a suture to the block, holding the suture stationary relative to the bone so as to hold the block in place and prevent the block from being inserted further into the intramedullary canal when the intramedullary member is inserted into the intramedullary canal.  
   
   
       18 . The process of  claim 16  additionally comprising providing said block with an aperture and guiding said block into the intramedullary canal by means of a guide wire extending through said aperture.  
   
   
       19 . The process of  claim 16  wherein the block is the canal diameter reducer defined in  claim 1 .  
   
   
       20 . The process of  claim 16  wherein the block is the canal diameter reducer defined in  claim 2 .  
   
   
       21 . The process of  claim 16  wherein the block is the canal diameter reducer defined in  claim 5 .  
   
   
       22 . The process of  claim 16  wherein the block is the canal diameter reducer defined in  claim 9.