| 主权项 |
1. An anchorage arrangement for a connecting plastic rod for surgical treatment of a spine, the anchorage arrangement comprising:
the connecting plastic rod including at least two plane-parallel surfaces; and a plurality of bone screws, each bone screw comprising a bottom side and sidewalls defining an opening, the opening positioned and configured to receive the connecting plastic rod; each bone screw comprising a ridge positioned in the opening; a clamping device comprising a clamping element and a spacer together positioned and configured to provide a clamping action in a direction parallel to the at least two plane-parallel surfaces so as to clamp an entire circumference of the rod; and the spacer comprising a spacer ridge; wherein a distance between the sidewalls is adapted to a distance of the plane-parallel surfaces in an area of contact so that the rod is snugly slidable in the opening, wherein, with the rod in the opening:
the ridge and the spacer ridge together comprise a continuous circumferential ridge projecting toward the rod,the continuous circumferential ridge entirely surrounds the rod,the entire length of the continuous circumferential ridge is in contact with the rod, anda contour of the bottom side and the sidewalls defined by the ridge coincide substantially with a cross-section of the rod and together with the spacer ridge compress the rod to produce hydrostatic properties for the rod according to the clamping action. |
