Patent ID: 6668688
Filing Date: 2003-12-30
Classification: A61B,B25B,F16B,Y10S

Abstract:
An expandable screw apparatus, comprising:an outer screw having a longitudinal hollow core and a plurality of longitudinal expandable slits proximate a distal end; an inner screw, disposed inside the longitudinal hollow core of the outer screw, having a distal end extended outside the longitudinal hollow core of the outer screw; said inner screw is threaded with one of a right handed orientation or a left handed orientation on an outer surface, and having opposite orientation to an outer surface of said outer screw; and an end nut, engaged with the distal end of the inner screw, wherein by rotating the outer screw relative to the inner screw while simultaneously holding the inner screw, the end nut is drawn into the hollow core of the outer screw, thereby causing simultaneous expansion of the expandable slits in a transversal direction.