| 摘要 |
A spinal implant assembly includes an elongated spinal implant, such as a rod, implanted adjacent the spine, and a bone fastener, such as a bone screw, engaged within a vertebra. A connection assembly includes a first member having a first opening for receiving the rod, and a second member having a second opening for receiving an elongated stem of the bone fastener. The two members are connected to permit relative rotation between the two members to accommodate variable angular orientations of the bone screw relative to the rod. A single washer is provided that has an opening for positioning over a portion of both the first member and the second member. One face of the washer is configured to engage the rod, while the opposite face of the washer is configured to engage the stem of the bone screw. In one embodiment, the opposite face of the washer defines a plurality of radial splines. The stem of the bone screw includes an interface element in the form of a rib that is configured to interdigitate with the radial splines. In another embodiment, the opposite face of the washer and the stem of the bone screw include interdigitating or interlocking raised features, such as knurling or cross-hatching. A set screw and threaded bore are provided in the first member, with the set screw bearing against the rod, which then bears against the washer and bone screw stem to clamp the assembly together. |
