Self drilling bone screw
AssigneeZimmer Spine, Inc.
InventorsGene Newcomb, Craig Hahne, Jason Piehl, Kevin Guenther
Life of this patent
Estimating the term…
Abstract
A self-drilling bone screw includes a screw body centered on a longitudinal axis and having an external thread winding. The bone screw has a head portion at one end of the screw body and a drill point at the other end. The drill point has two blades, each having a cutting lip and a primary relief surface trailing from the cutting lip. The two blades defining a flute between them. The flute has an opening to the side of the screw body, which opening spans an obtuse angle, such as about 120°, about the longitudinal axis. The primary relief surfaces have a lip relief angle of about 30°. The drill point has a point angle of about 100°.
Claims20
A bone anchor, comprising:
- an anchor body having proximal and distal ends;
- a head portion connected to the body at the proximal end;
- and
- a drill point connected to the body at the distal end, the drill point having a first and a second blades defining a flute between them with the first blade leading the second blade, each blade comprising:
- a cutting lip, and
- a primary relief surface trailing from the cutting lip and having a trailing edge,
- wherein the cutting lip of the second blade and the trailing edge of the primary relief surface of the first blade define an obtuse angle.
A bone screw, comprising:
- a screw body having two ends, at least a portion of the screw body having an external thread winding;
- a head portion connected to the screw body at one of the ends;
- and
- a drill point connected to the screw body at the other one of the ends, the drill point consisting of a first and a second blades
- defining a flute between them, the flute having an opening on a side wall of the screw body, the opening spanning an obtuse angle about a longitudinal axis of the screw body.
Dependencies are inferred from the claim text.