US 11,786,281 B2
Screw with a variable locking angle and a corresponding locking system
Janos Kodvanj, Zagreb (HR); and Srecko Sabalic, Zagreb (HR)
Assigned to ORTHOLOCK D.O.O., Zagreb (HR)
Filed by Janos Kodvanj, Zagreb (HR); and Srecko Sabalic, Zagreb (HR)
Filed on Jul. 15, 2021, as Appl. No. 17/376,176.
Application 17/376,176 is a continuation of application No. 17/159,146, filed on Jan. 27, 2021, granted, now 11,083,507.
Application 17/159,146 is a continuation of application No. PCT/EP2020/051202, filed on Jan. 18, 2020.
Claims priority of application No. P20190451A (HR), filed on Mar. 6, 2019.
Prior Publication US 2021/0338292 A1, Nov. 4, 2021
Int. Cl. A61B 17/80 (2006.01); A61B 17/86 (2006.01)
CPC A61B 17/8057 (2013.01) [A61B 17/8615 (2013.01); A61B 17/8635 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A screw with a variable locking angle into a bone plate, the screw comprising:
a screw head with carved surfaces and contact surfaces, as well as a centrally placed star-shaped socket to receive a fastening tool, located on an upper side of said screw head; and
a screw body ending with a tip portion to enter a bone first, where said screw body is equipped with a self-cutting thread which extends from a joint between the screw head and the screw body to the tip portion of the screw,
wherein said screw head is formed from a rotationally symmetric truncated cone of height h, with a base radius Rout on which said star-shaped socket is centrally positioned and where a cone side is inclined at an angle Y relative to an axis of said rotationally symmetric truncated cone which coincides with a screw axis of the screw,
wherein n of the carved surfaces, where n≥4, are carved into said rotationally symmetric truncated cone and extend from an upper edge of the screw head to a bottom edge of said screw head,
wherein said carved surfaces are interconnected with the contact surfaces of the rotationally symmetric truncated cone, both extending from the upper edge to the bottom edge of the screw head,
wherein the upper edge is partly formed from points of the contact surfaces that lie on the base radius Rout, and from upper edges of the carved surfaces in a way that a highest point of each said carved surface lies on a radius Rin in a plane parallel to a plane containing the base radius Rout, provided that Rin<Rout,
wherein the bottom edge is formed from ends of contact surfaces and the carved surfaces and leads to the joint between the screw head and the screw body,
wherein the screw head, with the carved surfaces and the contact surfaces, is formed without any thread on the carved surfaces and the contact surfaces, and
wherein the contact surfaces and the carved surfaces are adapted to be cut into and damaged by a thread of a bore when the screw is inserted into the bore.