Device for osteosynthesis
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. A device for osteosynthesis, comprising:
a fixation element having a through hole having a central axis and a cross section that extends orthogonally to the central axis and is one of at least partially polygonal, at least partially prismatic, and at least partially elliptical; and
a bushing insertable in said through hole, the bushing including a central bore structured to receive a bone fixation element, wherein a cross section of the bushing extending orthogonally to a longitudinal axis of the bushing is shaped substantially the same as the cross section of the through hole such that when the bushing is inserted in the through hole, it is secured against rotation about its longitudinal axis.
2. The device of claim 1 , wherein the cross section of the through hole is hexagonally shaped.
3. The device of claim 1 , wherein the through hole of the fixation element is prismatically shaped.
4. The device of claim 3 , wherein the through hole of the fixation element is shaped as a hexagonal prism.
5. The device of claim 1 , wherein the bore of the bushing tapers in one direction.
6. The device of claim 1 , wherein the bore of the bushing has a conical shape.
7. The device of claim 1 , wherein the bore of the bushing has a cylindrical shape.
8. The device of claim 1 , wherein the bore of the bushing has an internal thread.
9. The device of claim 1 , wherein the bushing has a continuous slot.