Fixed and variable locking fixation assembly
First Claim
1. A nonmetallic bone fixation plate having an anterior surface and a posterior surface, comprising:
- a metallic insert fixedly coupled to said plate wherein said metallic insert further comprises an anterior surface and a posterior surface, andwherein said insert further comprises a non-threaded through-hole through said anterior surface and said posterior surface of said insert,said non-threaded through-hole having associated therewith an imaginary longitudinal axis through the centroid of said non-threaded through-hole;
wherein said non-threaded through-hole comprises an entrance that has a proximal end and a distal end and an exit having a proximal end and a distal end; and
wherein at least a portion of said entrance and said exit are generally frusto-conical.
8 Assignments
0 Petitions
Accused Products
Abstract
A locking screw assembly is provided which allows installation into a plate-like member using relatively little force, but which requires relatively great force for removal. The fastener has an annular locking ring provided within a groove in the head of the screw to allow the screw to sit within or flush with the anterior surface of the plate. The through-hole in the plate which receives the locking screw comprises an entrance, a collar section, an undercut, and an exit. The locking ring resides within the undercut. The locking ring has a leading surface that is chamfered or radiused and a trailing surface that is flat. The chamfer allows the locking ring to easily be inserted into the through-hole by interacting with a lead chamfer in the entrance. After installation, the flat trailing surface abuts a lip adjoining the collar section and the undercut and prevents the screw from being easily removed from the through-hole.
363 Citations
12 Claims
-
1. A nonmetallic bone fixation plate having an anterior surface and a posterior surface, comprising:
-
a metallic insert fixedly coupled to said plate wherein said metallic insert further comprises an anterior surface and a posterior surface, and wherein said insert further comprises a non-threaded through-hole through said anterior surface and said posterior surface of said insert, said non-threaded through-hole having associated therewith an imaginary longitudinal axis through the centroid of said non-threaded through-hole; wherein said non-threaded through-hole comprises an entrance that has a proximal end and a distal end and an exit having a proximal end and a distal end; and wherein at least a portion of said entrance and said exit are generally frusto-conical. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
Specification