A bone-anchoring device is provided. The bone-anchoring device may comprise a screw including a threaded shaft portion configured to engage bone tissue, and a head portion having a cup-shaped cavity. The device may further include a rod connector and a linking member, wherein the linking member includes...http://www.google.com/patents/US7927359?utm_source=gb-gplus-sharePatent US7927359 - Polyaxial screw
