A device is provided on spinal fixation hook or screw elements along a spinal implant rod for preventing or inhibiting them from unintentional sliding on the rod during handling prior to implantation in vivo. One embodiment uses a set screw in an eyebolt and which engages the rod. Another uses a plastic...http://www.google.co.uk/patents/US5403315?utm_source=gb-gplus-sharePatent US5403315 - Positionable spinal fixation device
