Compression bone screw

Claim 2

A compression bone screw comprising: (a) a distal portion including a distal shaft having a plurality of distal threads therein, the distal threads having a given pitch, said distal portion terminating in a substantially pointed end; (b) a proximal portion including a proximal shaft having a diameter which is greater than the diameter of the distal shaft said proximal portion including a tool interengaging means thereon; and (c) an intermediate portion connecting the proximal portion and the distal portion, the intermediate portion including a tapered shaft having a threadless substantially annular smooth outer surface, wherein the tapered shaft and the distal threads cooperate so as to create opposing forces which effect compression of bone tissue between the intermediate portion and the distal portion when the distal threads and the tapered shaft are both engaging bone tissue.

Claim 3

The bone screw of claim 1 wherein the proximal shaft is cylindrical, the distal shaft is tapered and the cross-sectional diameter of the proximal shaft is greater than the largest cross-sectional diameter of the distal shaft.

Claim 4

The bone screw of claim 2 wherein the cross-sectional diameter of the proximal shaft is no smaller than the largest cross-sectional diameter of the distal threads.

Claim 5

The bone screw of claim 2 wherein the distal threads are provided with at least one self-cutting flute.

Claim 6

The bone screw of claim 4 wherein the distal portion terminates in a sharp trocar point.

Claim 7

The bone screw of claim 2 wherein the distal threads may be inserted into a bore formed longitudinally along the center axis of the fractured end of a bone and, by inserting the screw into the bore until the distal threads engage the bone on one side of the fracture and at least a part of the intermediate portion is engaging the bone on the opposite side of the fracture, a compressive force is established in the bone parallel to the length of the screw, said distal portion terminating in a sharp trocar point.

Claim 8

The bone screw of claim 1 wherein the proximal shaft has a plurality of proximal threads thereon, said proximal threads having a given pitch which is the same as the given pitch of the distal threads.

Claim 9

The bone screw of claim 7 wherein the proximal threads are provided with at least one self-cutting flute.

Claim 10

The bone screw of claim 1 wherein the proximal portion is provided with a recessed socket for engaging a tool.

Claim 11

The bone screw of claim 9 wherein said recessed socket is a recessed hexagonal opening.

Claim 12

A compression bone screw comprising: (a) a distal portion including a distal shaft having a plurality of distal threads thereon, the distal threads being provided with at least one self-cutting flute, the distal threads having a given pitch, and the distal portion terminating in a sharp trocar point; (b) a proximal portion including a cylindrical proximal shaft having a plurality of proximal threads thereon, the proximal threads having the same given pitch as the distal threads, the proximal shaft having a diameter which is greater than the largest cross-sectional diameter of the distal threads; and the proximal portion being provided with a recessed socket adapted to be engaged by a tool for rotating said screw; and (c) an intermediate portion connecting the proximal portion and the distal portion, the intermediate portion including a tapered shaft having a threadless substantially annular smooth outer surface, wherein the distal threads may be inserted into a bore formed longitudinally along the center axis of a fractured bone and, by inserting the screw into the bore until the distal threads engage the bone on one side of the fracture and at least a part of the intermediate portion is engaging the bone on the opposite side of the fracture, the tapered shaft and the distal threads cooperate so as to create opposing forces which effect compression of bone tissue between the intermediate portion and the distal portion, the compressive force thus established being parallel to the length of the bone and the length of the screw, with the screw further establishing axial alignment of the bone at the fracture site.

Claim 13

A compression bone screw comprising: (a) a distal portion including a distal shaft having a plurality of distal threads thereon, the distal threads being provided with at least one self-cutting flute, the distal threads having a given pitch, and the distal portion terminating in a sharp trocar point; (b) a proximal portion including a cylindrical proximal shaft having a plurality of proximal threads thereon, the proximal threads having the same given pitch as the distal threads, the proximal shaft having a diameter which is greater than the largest cross-sectional diameter of the distal threads; and the proximal portion being provided with a recessed socket adapted to be engaged by a tool for rotating said screw; and (c) an intermediate portion connecting the proximal portion and the distal portion, the intermediate portion including a tapered shaft having a threadless substantially annular smooth outer surface, wherein the distal threads may be inserted into a bore formed longitudinally along the center axis of a fractured bone and, by inserting the screw into the bore until the distal threads engage the bone on one side of the fracture and at least a part of the intermediate portion is engaging the bone on the opposite side of the fracture, the tapered shaft and the distal threads cooperate so as to create opposing forces which effect compression of bone tissue between the intermediate portion and the distal portion, the compressive force thus established being parallel to the length of the bone and the length of the screw, with the screw further establishing axial alignment of the bone at the fracture site.

Claim 14

The bone screw of claim 11, wherein said intermediate portion is of approximately the same length as said distal portion and said proximal portion.

Claim 15

A compression bone screw comprising: (a) a distal portion including a distal shaft having a plurality of distal threads thereon, the distal threads having a given pitch; (b) a proximal portion including a proximal shaft having a plurality of proximal threads thereon, the proximal shaft having a diameter which is greater than the diameter of the distal shaft, said proximal threads terminating about midway along said proximal shaft and (c) an intermediate portion connecting the proximal portion and the distal portion, the intermediate portion including a tapered shaft having a substantially smooth outer surface, wherein the tapered shaft and the distal threads cooperate so as to create opposing forces which effect compression of bone tissue between the intermediate portion and the distal portion when the distal threads and the tapered shaft are both engaging bone tissue, said intermediate portion being of a approximately the same length as said distal portion and said proximal portion.

Claim 16

A compression bone screw comprising: (a) a distal portion including a distal shaft having a plurality of distal threads thereon, the distal threads having a given pitch; (b) a proximal portion including a proximal shaft having a plurality of proximal threads thereon, the proximal shaft having a diameter which is greater than the diameter of the distal shaft, said proximal threads terminating about midway along said proximal shaft and (c) an intermediate portion connecting the proximal portion and the distal portion, the intermediate portion including a tapered shaft having a substantially smooth outer surface, wherein the tapered shaft and the distal threads cooperate so as to create opposing forces which effect compression of bone tissue between the intermediate portion and the distal portion when the distal threads and the tapered shaft are both engaging bone tissue, said intermediate portion being of a approximately the same length as said distal portion and said proximal portion.