A spinal implant having at least two bone anchors includes a longitudinal connecting member assembly having hard, non-elastic sleeves for attachment to the bone anchors, at least one spacer engaging the bone anchors and the sleeves, and in some embodiments, an end elastic bumper. A cord is initially slidingly received within the rigid sleeves, the spacer and the bumper. The sleeves include a lower radiused surface for direct engagement with a radiused surface of a shank of the cooperating bone anchor. The sleeves include an aperture for receiving a closure top portion for locking the cord against the sleeve, or alternatively receiving a closure top that does not extend into the aperture, the slip or grip option provided by the aperture in each sleeve resulting in an overall connector with variable segmental stiffness.
