Device for osteosynthesis

Abstract

The device for performing osteosynthesis includes a fixation element, such as a bone plate having a bottom surface designed to bear against the bone, a top surface, and at least one through hole extending from the bottom surface to the top surface, the though hole having a central axis and configured and dimensioned to receive a multiaxially pivotal insert or bushing for a bone screw. A bushing insertable into the through hole, includes a central bore designed to receive a bone screw, the central bore having a longitudinal axis, and a peripheral outer surface designed to be in contact with the through hole. The bushing is configured and dimensioned to be radially compressible and radially expansible, and the cross section of the through hole, which is orthogonal to the central axis, is non-circular. The cross section of the bushing that is orthogonal to the longitudinal axis has a shape that corresponds substantially to the cross section of the through hole of the bone plate. When placed in the through hole, the bushing is rotationally fixed relative to its longitudinal axis, but remains pivotally adjustable within the through hole relative to the bone plate.

1 - 51 . (canceled) 
     
     
         52 . A bone plate system, comprising:
 a bone plate having a bottom surface for contacting bone, an upper surface and a non-circular through hole extending from the bottom surface to the upper surface; and   a bushing mounted within the through hole, the bushing including a central bore sized and shaped to receive a bone fixation element, a shape of the bushing in a plane orthogonal to a central axis of the central bore is substantially the same shape the through hole so that the bushing is secured against rotation relative to the bone plate about its central axis; and   a bone fixation element having a shaft for anchoring within a bone and a head sized and shaped to be lockingly received within the central bore.   
     
     
         53 . The system of  claim 52 , wherein the through hole is hexagonal. 
     
     
         54 . The system of  claim 52 , wherein the bushing includes a slot extending therethrough from a top surface to a bone facing surface thereof. 
     
     
         55 . The system of  claim 52 , wherein the head of the bone fixation element is formed as a portion of a cone. 
     
     
         56 . The system of  claim 55 , wherein the bushing includes a macrostructured portion for lockingly engaging a corresponding macrostructured portion provided on an inner surface of the central bore. 
     
     
         57 . The system of  claim 56 , wherein the macrostructured portion includes peripheral ridges. 
     
     
         58 . The system of  claim 52 , wherein the bushing has a thickness from a top surface to a bone facing surface thereof less than a thickness of the bone plate from the upper to the bottom surface thereof. 
     
     
         59 . The system of  claim 52 , wherein the central bore of the bushing tapers between a top surface and a bone facing surface thereof. 
     
     
         60 . The system of  claim 52 , wherein the central bore of the bushing is one of conical and cylindrical. 
     
     
         61 . The system of  claim 52 , wherein the central bore of the bushing has an internal thread that mates with an external thread on the head of the bone fixation element. 
     
     
         62 . A bone plate system, comprising:
 a bone plate having a lower surface for contacting bone, an upper surface and a through hole extending from the lower surface to the upper surface, a radially inner surface of the through hole including a plurality of peripheral ridges;   a radially compressible bushing insertable in the through hole, the bushing comprising a top surface, a bottom surface which, when the bushing is received in the bone plate in a desired configuration, faces the same direction as the lower surface of the bone plate, the bushing including a central bore shaped and sized to receive a bone screw and a plurality of peripheral ridges formed on a peripheral surface thereof to engage the ridges of the through hole, a shape of the bushing being substantially the same as a shape of the through hole such that the bushing is non-rotatable about a central axis of the central bore relative to the through hole; and   a bone fixation element having a shaft for extending out of the bone plate into a target portion of bone and a head configured and dimensioned to be lockingly received in the central bore of the bushing.   
     
     
         63 . The system of  claim 62 , wherein a slot extends through the bushing from the top surface to the bottom surface thereof. 
     
     
         64 . The system of  claim 63 , wherein the slot extends parallel to the central axis of the central bore. 
     
     
         65 . The system of  claim 62 , wherein the screw head is conically tapered. 
     
     
         66 . The system of  claim 65 , wherein the screw head includes threading. 
     
     
         67 . The system of  claim 62 , wherein a thickness of the bushing from the top surface to the bottom surface is less than a thickness of the bone plate at the through hole from the upper surface to the lower surface. 
     
     
         68 . The system of  claim 62 , wherein the bone plate comprises a plurality of through holes and a plurality of bushings insertable thereinto.