| 摘要 |
Fixed and polyaxial bone attachment assemblies include a receiver with a pair of spaced arms defining a open channel for receiving a longitudinal connecting member. Inner surfaces of the arms have a flangeform discontinuous guide and advancement structure for receiving a closure structure, the longitudinal connecting member being captured in the receiver by the closure structure. The longitudinal connecting member receiving surface includes a bottom seat disposed opposite an opening of the channel and a pair of curved substantially opposed side surfaces facing toward one another on either side of the bottom seat. At least one projection extends from one of the side surfaces, the projection having a sharp end. Upon assembly with a longitudinal connecting member, such as a cylindrical rod, the projection sharp end engages and penetrates the surface of the longitudinal connecting member, guarding against translational and rotational movement of the rod within the receiver. The projection or projections are disposed either directly on a receiver or on a compression insert pre-loaded into the receiver.
|
