Bone screw with means for guiding a screwdriver

摘要

A bone anchor including a bone engaging portion and an elongate guiding portion. In one embodiment, the bone engaging portion includes a cannula passage extending at least partially through the bone engaging portion, and at least one transverse opening in communication with the cannula passage. The elongate guiding portion extends from the bone engaging portion and is configured to guide a device into engagement with the bone engaging portion.