A pedicle screw configured to secure a rod is disclosed. In some embodiments, the pedicle screw is provided with a shaft, a yoke, a cap, a saddle and at least one separating device. The shaft has a forward end, a rear end and a longitudinal axis, the forward end being configured for insertion into a bone. The yoke is attached to the rear end of the shaft and has an interior wall nearest the shaft configured to bear against a rod inserted into the yoke. The cap is configured to engage an end of the yoke opposite the shaft. The saddle has a first side configured to mate with the cap within the yoke, and has an opposite second side configured to bear against the rod. The at least one separating device is coupled between the cap and the saddle, and is configured to urge the cap and the saddle apart from one another. With this arrangement, the yoke, the cap, the saddle and the at least one separating device cooperate to urge the rod against the interior wall of the yoke when the at least one separating device urges the cap and the saddle apart. Methods of securing a rod to a pedicle screw are also disclosed.
