| 摘要 |
A spinal fixation system includes a relatively rigid fixation plate which is engaged to a plurality of vertebrae by bone screws or bolts. The plate includes a longitudinal slot defined therethrough with an arrangement of scallops formed at the edge of the slot on the upper and lower surfaces of the plate. The scallop arrangement includes a first set of scallops formed at one spherical radius and a second set of scallops nested within the first that are formed at a smaller radius. Thus, the fixation plate can accommodate bone screws or bolts, or other bone engagement or load transmitting components having curved engagement surfaces of various diameters and providing varying degrees of rigidity. In another feature of the invention, a C-shaped ring is provided which encircles the plate to entrap the side walls of the plate, thereby restricting the plate walls from spreading as the bone screws or bolts are tightened onto the plate. The side walls of the plate and the inner walls of the C-shaped ring are correspondingly curved to retain the ring on the plate.
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