Patent ID: 8162998

Claim:
A bone screw having a distal end and a proximal end comprising: a shaft with a core diameter “k” and having an external thread with an external diameter “d”, the shaft comprising: a first elongated part extending from a first end to a second end of the bone screw, the first part having a first length and a uniform external diameter “d 2 ” and uniform core diameter “k 2 ”; a second elongated part extending from a third end to a distal end of the bone screw, the second elongated part having a second length and a uniform external diameter“d 1 ” and uniform core diameter “k 1 ”; a tapered part extending from the second end to the third end of the bone screw, the tapered part tapering from the larger dimensions “d 2 ” and “k 2 ” respectively towards the smaller dimensions “d 1 ” and “k 1 ”, respectively, where “d 1 ” and “k 1 ” do not equal zero, wherein the shaft is provided with a concentrically disposed, radially expandable sleeve, and wherein the sleeve is positioned on the part of the shaft which has the smaller external diameter “d 1 ”.