Importance

Loading Importance Indicators...

Abstract

The invention concerns a bone screw having a distal end and a proximal end, which has the distinguishing features a shaft with a core diameter “k” and having an external thread with an external diameter “d”. The external diameter “d” of the thread or the core diameter “k” of the shaft tapers in a middle region of the shaft from a larger dimension “d₂” or “k₂” respectively towards the proximal end to a smaller dimension “d₁” or “k₁”, respectively, where “d₁” and “k₁” do not equal zero. Further, the shaft is provided with a concentrically disposed, radially expandable sleeve, and the sleeve being positioned on the part of the shaft which has the smaller external diameter “d₁”. The bone screw may be introduced into a transverse borehole of a medullary pin. The medullary pin is provided with a continuous cannulation, which extends coaxially with the longitudinal axis of the medullary pin and has an external diameter D_N and a wall thickness W_N. The transverse borehole may have a diameter D_B, which is larger than d₂ as well as larger than d_B-L5. In one embodiment, diameter D_B may be approximately 90% of the diameter d_B-L3 of the sleeve. The sleeve may be inserted completely into the transverse borehole and, with the flange, is in contact with the wall of a facet of the transverse borehole.

Loading the Abstract Image...

First Claim