A twist-drivable pin assembly

Abstract

A twist-drivable pin assembly includes first and second drivers, each having a driving end ( 2 ) which can be received in a bore ( 104 ) in the end of a twist-drivable pin, and an opposite end at which torque can be applied. The cross-sectional shape of each of the drivers at its driving end has a first plurality of apexes ( 18 ) whose relative locations coincide with the apexes of a regular polygon such as a hexagon. The drivers differ from one another in their cross-sectional shapes at the driving end by virtue of one or more faces of at least one of the drivers between adjacent pairs of apexes having a groove ( 20 ) formed in it. Each of first and second twist-drivable pins has a bore ( 64 ) extending into it which is defined by a second plurality of apexes arranged as a regular polygon such as a hexagon and which is open at one end. The number of apexes of the second plurality is equal to the number of apexes of the first plurality. The first and second pins differ from one another by virtue of markings associated with the open ends of the polygonal bores. The shape defined by the markings corresponds to the cross-sectional shape of a corresponding one of the first and second drivers.

1 - 14 . (canceled) 
     
     
         15 . A twist-drivable pin assembly comprising:
 a. first and second drivers, each of which has a driving end which can be received in a bore in the end of a twist-drivable pin, and an opposite end at which torque can be applied, the cross-sectional shape of each of the drivers at its driving end having a first plurality of apexes whose relative locations coincide with the apexes of a regular polygon, one or more of the faces between adjacent pairs of apexes of at least one of the drivers having a groove formed in it so that the drivers differ from one another in their cross-sectional shapes at the driving end by virtue of the provision of different numbers and/or arrangements of such grooves,   b. first and second twist-drivable pins, each having a bore extending into it which is defined by a second plurality of apexes arranged as a regular polygon and which is open at one end, in which at least one of the drivers can be received, the number of apexes of the second plurality being equal to the number of apexes of the first plurality, the first and second pins differing from one another by virtue of markings associated with the open end of the polygonal bore of at least one of the first and second pins, in which the shape defined by the markings corresponds to the cross-sectional shape of a corresponding one of the first and second drivers.   
     
     
         16 . The twist-drivable pin assembly of  claim 15 , in which the markings on at least one of the pins defines a shape which is different from the shape of the bore in that pin. 
     
     
         17 . The twist-drivable pin assembly of  claim 15 , in which the markings on one or each of the first and second twist-drivable pins are formed by removing material from the surface of the pins surrounding the open end of the bore. 
     
     
         18 . The twist-drivable pin assembly of  claim 17 , which the marks are formed by engraving. 
     
     
         19 . The twist-drivable pin assembly of  claim 17 , in which the marks are formed using a laser. 
     
     
         20 . The twist-drivable pin assembly of  claim 17 , in which the depth of the markings below the surface of the twist-drivable pins the bore is at least about 0.3 mm. 
     
     
         21 . The twist-drivable pin assembly of  claim 17 , in which the depth of the markings below the surface of the twist-drivable pins surrounding the bore is not more than about 5.0 mm. 
     
     
         22 . The twist-drivable pin assembly of  claim 17 , in which the markings are provided on the twist-drivable pins in areas surrounding the open end of the hexagonal bore which lie radially outside of the straight lines joining adjacent apexes of the bore. 
     
     
         23 . The twist-drivable pin assembly of  claim 15 , in which the cross-sectional shape of each of the drivers at its driving end has six apexes whose relative locations coincide with the apexes of a regular hexagon. 
     
     
         24 . The twist-drivable pin assembly of  claim 15 , in which the grooves formed in one or each of the drivers by which the drivers differ from one another extend to the driving end of the drivers. 
     
     
         25 . The twist-drivable pin assembly of  claim 15 , in which the transverse dimension of the polygonal driving end of the first driver is different from the transverse dimension of the polygonal driving end of the second driver. 
     
     
         26 . The twist-drivable pin assembly of  claim 15 , in which the first and second twist-drivable pins are fasteners. 
     
     
         27 . The twist-drivable pin assembly of  claim 26 , in which each of the fasteners has an external thread. 
     
     
         28 . The twist-drivable pin assembly of  claim 15 , in which at least one of the twist-drivable pins is a shaft component of an instrument or device. 
     
     
         29 . A kit for use in surgery including an orthopaedic implant having at least one bore formed in it for receiving a twist-drivable pin and a twist-drivable pin assembly as claimed in  claim 15 .