Devices and method for widening bone cavities

Abstract

An widening device for bone cavities extends from a proximal end to a distal end along an extension axis, said distal end having an elastically deformable element suitable to pass from a relaxed configuration for placing the distal end within an osteal body to a deformed configuration for forming a cavity within said osteal body. The elastically deformable element permits to create a bone cavity in a regular and uniform way.

1 . Widening device for bone cavities extending from a proximal end to a distal end along an extension axis, said distal end comprising an elastically deformable element, suitable to pass from a relaxed configuration for the positioning of the distal end within an osteal body to a deformed configuration to form a cavity within said osteal body, 
 said elastically deformable element comprises at least one tab suitable for widening a bone cavity by passing from a relaxed configuration to a deformed configuration,    wherein said elastically deformable element extends from a first collar to a second collar so that while said first and second collars approach to each other along said extension axis, said at least one tab bends in order to widen said internal cavity of the osteal body.    
     
     
         2 . Widening device according to  claim 1 , wherein said at least one tab has, along its longitudinal extension, a thickness, as measured relative to a radial direction incident to said extension axis and contained in perpendicular plane to said extension axis, variable along the extension axis such as to vary the stiffness of at least one tab along the extension thereof.  
     
     
         3 . Widening device according to  claim 2 , wherein said tab comprises a central portion and two side portions relative to said extension axis, opposite to said central portion, at least one of said side portions having a radial thickness other than the radial thickness of the central portion.  
     
     
         4 . Widening device according to  claim 3 , wherein at least one tab comprises a central portion having a radial thickness decreasing towards the side portions.  
     
     
         5 . Widening device according to  claim 1 , comprising a plurality of tabs separated from one another by means of grooves.  
     
     
         6 . Widening device according to  claim 5 , wherein said grooves comprise slots at axial ends of the tabs.  
     
     
         7 . Widening device according to  claim 1 , wherein said tabs are arranged in an axial-symmetrical manner relative to said extension axis.  
     
     
         8 . Widening device according to  claim 1 , wherein said tabs are arranged in an asymmetrical manner relative to said extension axis.  
     
     
         9 . Widening device according to  claim 1 , wherein a sheath suitable to cover said tabs is mechanically associated to said elastically deformable portion.  
     
     
         10 . Widening device according to  claim 9 , wherein said sheath, in a relaxed configuration, is at least partially separated from said tabs.  
     
     
         11 . Widening device according to  claim 9 , wherein said sheath has a radial thickness varying along the extension axis.  
     
     
         12 . Widening device according to  claim 1  or  2 , wherein the elastically deformable element comprises at least one tab having a prevalent extension along a median line, between a first collar and a second collar, said median line extending so that a line, which is parallel to extension axis and which passes through an intersection point between the tab and the first collar, does not pass through an intersection point between the tab and the second collar.  
     
     
         13 . Widening device according to  claim 1  or  2 , wherein said elastically deformable element comprises at least one tab having a predefined extension along a median line, said median line extending along a helicoidal path with respect to said extension axis.  
     
     
         14 . Widening device according to  claim 13 , wherein said median line extends according to a helix angle, said helix angle being defined between a line perpendicular to a line parallel to extension axis and passing through said median axis, and said median axis.  
     
     
         15 . Widening device according to  claim 14 , wherein said helix angle is comprised between 60 and 85 degrees.  
     
     
         16 . Widening device according to  claim 15 , wherein said helix angle is equal to 80 degrees.  
     
     
         17 . Widening device according to  claim 14 , wherein said helix angle is constant, along the extension of the tab.  
     
     
         18 . Widening device according to  claim 14 , wherein the helix angle is variable along the extension of the tab.  
     
     
         19 . Widening device according to  claim 18 , wherein the helix angle is greater near first and second collars which delimit axially the elastically deformable element.  
     
     
         20 . Widening device according  claim 1 , comprising a cannula tubular, suitable for permit the passage of said elastically deformable element, in a relaxed configuration, into said cannula, for the insertion in said osteal body.  
     
     
         21 . Widening device according to  claim 20 , wherein said cannula comprises a gripping end suitable to be firmly made integral to the osteal cortical area, and a connecting end comprising a bush suitable to be connected to said widening device.  
     
     
         22 . Widening device according to  claim 21 , wherein said bush is suitable for being mechanically and selectively connected to a widening device for bone cavities, to a cement injection device and to a funnel for bone bits or bone substitute to be inserted within said bone cavity.  
     
     
         23 . Method for widening an osteal body comprising the steps of: 
 making a cannula having a gripping end and a connecting end provided with a bush integral to the cortical area of an osteal body,    inserting in said cannula a widening device for bone cavities mechanically connected by means of said bush,    activating the widening device to form a bone cavity,    deactivating and disable the widening device,    inserting in said cannula a cement injection device mechanically connected by means of said bush,    injecting cement in the bone cavity.    
     
     
         24 . Method for widening an osteal body comprising the steps of: 
 making a cannula having a gripping end and a connecting end provided with a bush integral to the cortical area of an osteal body,    inserting in said cannula a widening device mechanically connected by means of said bush,    activating the widening device to create a bone cavity,    deactivating and disabling the widening device,    inserting in said cannula a funnel mechanically connected by means of said bush,    inserting bone bits or bone substitute in the bone cavity, through said funnel.    
     
     
         25 . Method according to  claim 23  or  24 , wherein said widening device is a widening device according to  claim 1.