Variable angle locking implant

Abstract

A variable angle locking implant includes a bone plate having a lower surface, an upper surface, and at least one opening extending from the lower surface to the upper surface along an axis. The opening has a plurality of fins oriented along a plane. The axis is non-perpendicular to a tangent of a projection of the lower surface across the opening, the tangent defined at the intersection between the axis and the projected lower surface, and/or the plane is non-parallel to the tangent. The implant includes at least one fastener, and the plurality of fins are deflectable relative to a head portion of the fastener such that the fastener can be inserted and retained at any one of a plurality of angles.

What is claimed is: 
     
         1 . A variable angle locking implant comprising:
 a bone plate having a lower surface;
 an upper surface; and 
 at least one opening extending from the lower surface to the upper surface along an axis, the at least one opening having an inner surface with a plurality of fins circumferentially disposed about the inner surface, the plurality of fins being disposed exclusively in first and second rows, the first row of fins lying in a first plane to contact a head portion of a fastener in use and the second row of fins lying in a second plane to contact the head portion of the fastener in use, the first row of fins being positioned closer to the upper surface of the bone plate and the second row of fins being positioned closer to the lower surface of the bone plate; 
 wherein the first row of fins define a first edge including a series of concave and convex portions, and the second row of fins define a second edge including a series of concave and convex portions. 
   
     
     
         2 . The implant of  claim 1 , wherein the first row of fins defines a first circumferential edge including a series of concave and convex surfaces, and the second row of fins define a second circumferential edge including a series of concave and convex surfaces. 
     
     
         3 . The implant of  claim 1 , wherein the first plane and the second plane are parallel relative to each other. 
     
     
         4 . The implant of  claim 3 , wherein the first plane and the second plane are parallel to the lower surface of the bone plate. 
     
     
         5 . The implant of  claim 1 , wherein the axis of the at least one opening is oriented non-perpendicular to the lower surface of the bone plate. 
     
     
         6 . The implant of  claim 1 , wherein the plurality of fins include inwardly tapered side surfaces. 
     
     
         7 . The implant of  claim 1 , wherein the plurality of fins each have a tapered surface extending from the inner surface of the at least one opening to a terminal end of the fin. 
     
     
         8 . The implant of  claim 1 , wherein the at least one opening has a radius between the inner surface and a top surface of the first row of fins, and each fin tapers in thickness from the inner surface towards a terminal end. 
     
     
         9 . The implant of  claim 1 , further comprising at least one fastener arranged and configured to be inserted into the at least one opening in use, the at least one fastener including a partially threaded head portion and a partially threaded shaft portion;
 wherein, when the at least one fastener is inserted into the at least one opening, the plurality of fins are deformable in a direction coincident with the axis of the at least one opening so that the fastener is retained at any one of a plurality of angles relative to the at least one opening.   
     
     
         10 . An implant comprising:
 a first surface;   a second surface; and   at least one opening extending from the first surface to the second surface, the at least one opening having an inner surface including a first plate member including a plurality of upper fins and a second plate member including a plurality of lower fins, wherein the plurality of upper fins define an upper, circumferential edge to contact a head of a bone fastener in use and the plurality of lower fins define a lower, circumferential edge to contact the head of the bone fastener in use, the plurality of upper fins are positioned closer to the first surface of the implant and the plurality of lower fins are positioned closer to the second surface of the implant; and   wherein at least one of the plurality of upper fins and the plurality of lower fins are adapted and configured to deform in order to secure a position of the head of the bone fastener inserted into the at least one opening.   
     
     
         11 . The implant of  claim 10 , wherein the at least one opening includes an axis, the axis of the at least one opening is oriented non-perpendicular to the first and second surfaces of the implant. 
     
     
         12 . The implant of  claim 10 , wherein the implant is a bone plate. 
     
     
         13 . The implant of  claim 10 , wherein the implant is an acetabular cup. 
     
     
         14 . The implant of  claim 10 , wherein at least one of the plurality of upper fins and at least one of the plurality of lower fins cooperate with the head of the bone fastener. 
     
     
         15 . The implant of  claim 10 , wherein each of the plurality of upper fins and each of the plurality of lower fins cooperate with the head of the bone fastener. 
     
     
         16 . The implant of  claim 10 , wherein the plurality of upper fins lie in a first plane and the plurality of lower fins lie in a second plane, the first plane and the second plane being parallel relative to each other. 
     
     
         17 . The implant of  claim 10 , wherein the plurality of upper fins lie in a first plane and the plurality of lower fins lie in a second plane, the first plane and the second plane being parallel to the second surface of the implant. 
     
     
         18 . The implant of  claim 10 , wherein the plurality of upper fins and the plurality of lower fins are provided as a series of concavely indented, inwardly protruding fins. 
     
     
         19 . The implant of  claim 10 , wherein the first and second plate members are integrally formed with the bone plate. 
     
     
         20 . A bone plate system comprising:
 a bone plate including an upper surface;
 a lower surface; and 
 at least one opening extending from the lower surface to the upper surface, the at least one opening having an inner surface consisting of a plurality of first fins and a plurality of second fins; 
 wherein: 
 the plurality of first fins are circumferentially disposed about the inner surface, the plurality of circumferentially disposed first fins defining a first circumferential surface including a series of concave and convex surfaces; 
 the plurality of second fins are circumferentially disposed about the inner surface, the plurality of circumferentially disposed second fins defining a second circumferential surface including a series of concave and convex surfaces; 
 the plurality of first fins are closer to the upper surface than the plurality of second fins; and 
 wherein the plurality of first fins and the plurality of second fins are adapted and configured to deform in order to secure a position of a head portion of a bone fastener inserted into the at least one opening.