Patent ID: 8900272

Claim:
A polyaxial bone screw assembly comprising: a) a shank having lower structure adapted for anchoring to a bone of a patient and an upper end with an internal drive socket recess therein; b) a receiver having an interior cavity that operably receives the shank upper end and an upper channel having a top surface for receiving a connecting member; c) a pressure insert operably located in the cavity and at least partially between the shank and the connecting member when the connecting member is located in the channel; the pressure insert having upstanding legs that are sized and shaped to extend around and above the connecting member when the connecting member is located in the channel; each of the legs having an upper surface; and d) a closure comprising a closed outer ring and an inner set screw, that in use are both being received within the receiver so as to not extend above said channel top surface and so that the outer ring operably engages and applies downward force to the legs at each insert upper surface when the outer ring is rotatably advanced towards the pressure insert, so as to lock the shank with respect to the receiver independent of the connecting member, and wherein the inner set screw includes a central multi-surfaced drive aperture opening only onto a flat top surface thereof and having an interior lower tool abutment surface near a bottom surface of the inner set screw.